1 - The Natural History Museum, London
Most gemstones are chosen for their hardness and stability as well as their beauty, but a surprising number happen to be rather inadvisable choices. Some are toxic or can produce corrosive liquids, others will change colour when exposed to light or deteriorate if not stored at specific relative humidity or without oxygen. This poster explores some examples of jewellery made of difficult materials (such as opal and meteoric iron), less robust materials (such as sulphur and amber), and frankly bonkers materials (such as pyrite and halite). Causes of deterioration as well as advice on storage and treatment are presented.
1 - University of Birmingham 2 - Indian Institute of Technology Bhubaneswar 3 - University of Liberal Arts Bangladesh
The Sundarbans, a UNESCO world heritage site spanning Bangladesh and India, boasts a rich array of flora and fauna within its unique mangrove ecosystem. Holocene sea-level fluctuations have preserved diverse vertebrate remains in the Bengal basin's peat deposits. Despite the typically acidic peaty soils that dissolve calcium phosphates in bones, the relatively young age of these remains has minimized diagenetic effects. In 2022, a local report detailed the discovery of a crocodile remains from late Holocene (equivalent to Meghalayan age) peaty soil in Satkhira district, which caught our attention. Consequently, our team from the "Bangladesh Academy of Geological Sciences" was dispatched to collect and preserve the specimen. The bones were carefully rolled in toilet paper and transported to our temporary lab, where they were air-dried, cleaned with acetone, and coated with polyvinyl acetate resin adhesive. Bones with microfractures received an additional layer of water-diluted adhesive in a 1:1 ratio. Vertebrate fossil preparation is a novel practice in Bangladesh, with only rudimentary facilities available. Our meticulous approach convinced the National Museum of Bangladesh to accession their first palaeontological specimens from us and greatly appreciated our efforts. This donation signifies the commencement of a new era in specimen acquisition, conservation, and research within Bangladesh. Additionally, it encourages public interest in exploring the Sundarbans' ancient heritage. The success of this project highlights the potential for future investments in palaeontological research and conservation, fostering a deeper understanding of Sundarban's ancient heritage.
1 - University of Manchester 2 - Natural History Conservation
A large ichthyosaur skull found at Lyme Regis, Dorset, in 1813 by 14-year-old Mary Anning has been in the Bristol Museum & Art Gallery collection since 1844. The Temnodontosaurus specimen has had deep cracks since its discovery and records show that the lower half has been encased in deep mortar within a wooden frame since at least the 1930s. For the new permanent exhibition that opened in January 2024 ('Making Waves - Mary Anning and her astonishing ichthyosaur') the specimen was carefully removed from the old frame, cleaned, conserved and mounted. This necessitated turning it upside-down temporarily so that a new permanent mount could be made. Yet this historically significant specimen was heavily cracked and weighed a third of a ton. This presented some challenges. The specimen was 3D scanned before work started and scanned again when work was complete. The detailed digital 3D model of the first scan provides a historical record of the specimen as it was before work commenced. The scan of the cleaned and conserved specimen – without any mount etc in the way – provides a complete record of the specimen. This can be used for research and provides a benchmark for the condition of the specimen against which its condition can be assessed in the future. Significantly, several large unhealed toothmarks on both sides of the skull had been hidden by the mortar for all these years. These provide strong evidence of the large ichthyosaur being attacked (and possibly killed) by another large marine reptile.
1 - plesiosaur.com
The lower jaw of a rhomaleosaurid plesiosaur was discovered in the lowermost Lias at Lavernock by Matthew Myerscough in 2022 and brought to the attention of Amgueddfa Cymru (National Museum Wales). Permission was obtained from Cyfoeth Naturiol Cymru (Natural Resouces Wales) and the specimen was recovered shortly after its discovery. Although incomplete and poorly preserved, the specimen was considered significant enough to warrant careful preparation as it sheds light on the evolutionary history of plesiosaurs in general and Rhomalesaurs in particular. The preparation presents a number of problems. Parts of the jaw had already been eroded out by the ferocious tidal flow at Lavernock, leaving a partial mould in the matrix. Other very friable parts of the bone disintegrated when rinsed to remove salt. The extent of preserved bone was initially unclear but proved to be extensive and three dimensional . Preparation has been slow as bone needs to be consolidated as soon as it is exposed to prevent fragmenting. When possible lost sections were moulded in Jesmonite. The matrix around the bone is packed with crinoid fragments, which is unusual for fossils from the Lias. This, and the preservation of the bone, highlights the unusual taphonomic history of the specimen which is unlike that of other Liassic fossils.
1 - The Natural History Museum, London
Fossil preparation is generally divided into mechanical (using handheld tools) and chemical (e.g., using acids) techniques; increasingly, virtual techniques can also be employed, such as using CT scanning to create an image of fossil material within the matrix. Although it could be argued that virtual preparation can replace the need for physical preparation, at present such cases are rare. Far from being mutually exclusive, physical, chemical and virtual techniques can be combined to great success, with digital imagery being used as a guide to how best to undertake the physical preparation. As an example, micropreparation of Cretaceous shark teeth was recently carried out at the Natural History Museum, London. The researcher first CT scanned the specimens, small shark skulls in chalk, revealing tiny (<1cm) loose teeth within the matrix that if removed could be used to aid taxonomic studies. Using the CT scans to pinpoint the location, the preparator used a pin vice to carefully cut out a cube of matrix. The chalk cube was then transferred to dilute (2%) acetic acid. Once the tooth was free, it was placed on a slide and photographed with a microscope camera. The successful preparation could not have been possible without the combined application of virtual, physical and chemical techniques - and the communication between preparator, researcher and curator.
1 - La Brea Tar Pits Museum
Rancho La Brea (RLB) located in California, is the world's richest terrestrial Pleistocene fossil locality, renowned for its abundance of specimens and excellent preservation resulting from asphalt taphonomy. Fewer than 15 fossiliferous asphaltic deposits are known globally, which makes the preparation of such paleontological specimens highly specialized. The RLB Fossil Lab is the only technical facility in the world skilled in the large-scale preparation and conservation of asphaltic fossils. RLB has been engaged in active research focused on improving asphaltic preparation and conservation techniques. Our current preparation protocol requires careful application of a degreasing solvent, Novec 73DE, to adhering matrix, thereby softening the asphalt and loosening the sediment for easy mechanical separation from the specimens. The liberated matrix is later sorted to separate diverse biological specimens, measuring ~ 1cm-1mm in size, from the geological material with the use of a microscope. Conservation of fragile material plays an important role in the preservation of these fossils both in the initial exhumation of the specimen from the enclosing matrix, as well as historic specimens requiring remedial action. Paraloid B-72 mixed with acetone is the currently preferred adhesive, with Kozo paper and acrylic films applied in the restoration of fossils that have no secure connection points. The Fossil Lab is a publicly-viewable exhibition supported by an extensive volunteer cohort; ?40 people in 2024. Volunteers undergo hands-on training in all aspects of preparation, conservation and microfossil sorting and are provided access to a training manual that accompanies the physical training, further enhancing their skills development.
In 2018, T?hura Otago Museum received a request regarding a track of seven footprints found in clay in the Maniototo Conglomerate Formation in the Kyeburn River, Central Otago, New Zealand. The tracks were dated to at least 3.57 Ma (+1.62/-1.18Ma); the second earliest fossil record of moa and the first known discovery of moa footprints in the South Island of New Zealand. Due to their significance, the riverbed’s soft nature, and previous destructive flooding, a decision was made to excavate the footprints for further research and preservation. The excavation involved scientists and local M?ori from K?ti Huirapa R?naka ki Puketeraki who have an interest generally in te taiao (the natural world) within their rohe (tribal area) and historically. Footprints would have been an important tohu (sign) to their ancestors who would have used the footprints of moa prior to their extinction to track these giant birds. Traditionally, moa were an important resource and despite their extinction 600 years ago, have remained culturally important. With limited precedent, creating a mindful and sensitive conservation treatment with high publicity was a challenge. This paper discusses both treatment considerations and cultural ethics. Are the footprints natural science fossils, or are they cultural objects? What materials were best suited for treatment and storage? What story are we emphasizing? Was it just the footprints which are inherently important, or are the entirety of the excavated blocks, even the cutmarks, part of a story worth protecting? And the most challenging: who, if anyone, takes stewardship of them? Answers are found through theory, communication, and the respect of different perspectives.
1 - Iron Hill Science Centre, Delaware
In 2018, the Iron Hill Science Center in Newark, Delaware sent one of their ammonite fossils to the University of Delaware for conservation treatment. The Science Center has limited staff, none of whom are conservators or paleontologists. This treatment was to be used as experiential training for students in the undergraduate Art Conservation program. Over the course of four years, five students supervised by two different professors treated the fossil. This presentation will examine the stages of that work including addressing previous treatment, removal of matrix, stabilization of remaining material, fill creation, and visual integration efforts. Throughout the presentation, there will also be a focus on how this approach compares to a more traditional paleontological preparation, including post-treatment reflections and input from practicing paleontologists. Large, paleontology focused collections often have the benefit of ample material and purpose-based resources to complete conservation work. Looking at how smaller institutions such as the Iron Hill Science Center achieved their goals for the specimen via a student lab without paleontological supplies will be a window into some of the common problems that people run into when doing paleontology prep and conservation, and how people with relatively little background on the subject approached problem solving. What approaches could have been considered but weren’t? How did having a procession of student workers affect the treatment? This is a case study of applying other conservation principles to a paleontological object and of learning the process of prep through trial and error.
1 - Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Portugal; CERENA, Centro de Recursos Naturais e Ambiente, Instituto Superior Técnico, Universidade de Lisboa, Portugal. 2 - Laboratório de Paleontologia e Paleoecologia, Sociedade de História Natural, Santa Cruz, Torres Vedras, Portugal; 3 - NOVA School of Science and Technology, Department of Earth Sciences, Quinta da Torre, 2829-516 Caparica, Portugal 4 - Câmara Municipal de Loulé 5 - Geoparque Algarvensis 6 - GeoBioTec ‐ FCT-NOVA, Campus da Caparica, 2829‐516 Caparica, Portugal 7 - Universidade do Algarve, CIMA - Centro de Investigação Marinha e Ambiental, Campus de Gambelas, 8005-139, Faro, Portugal
Under the auspices of the DinoDawn Project, we recently prospected for fossil vertebrates and localities from the Formation of Silves Mudstones and Evaporitic Limestones to identify sites with excavation potential to conduct fieldwork in the long term. New fossil bonebeds and microvertebrate sites have been found from the Triassic formations of Algarve, South Portugal. These bonebeds are thin lenses of fine-grained rock that in some cases extend for over one hundred meters. The localities comprehend São Bartolomeu de Messines and Vale do Álamo. New microvertebrate to meso-scale vertebrates have been identified in Penina constrained to small pockets of mudstone, and preliminary sampling revealed a rich and diverse fauna. From these sites placodont, phytosaur, aetosaur and freshwater hybodontids remains have been retrieved, but given the seasonal drying pond paleoenvironments interpreted for nearby localities, potential for early dinosaur and mammaliaforms are likely to be found. However, our multidisciplinary team will include detailed paleoenvironemental reconstruction, high-resolution stratigraphy/cartography and palynology. We prospected multiple Triassic outcrops from West to East in the Algarve, covering the entire region, i.e., Cabo de São Vicente to Manta Rota; however, the concentration of macro- and microvertebrate fossils is within and around the Loulé Municipality.
1 - University of Bristol
Hornsleasow Quarry in Gloucestershire was the subject of a large systematic palaeontological excavation in the late twentieth century, following the initial discovery of large Cetiosaurus bones. The clay lenses of the middle Bathonian, middle Jurassic, Chipping Norton Formation were found to have an impressive abundance and diversity of well-preserved fossil microvertebrate remains from both terrestrial and freshwater groups. However this collection, stored in museum collections for over 30 years, received minimal attention and was never properly identified or imaged, until now. We find a rich diversity across multiple vertebrate groups. Crocodile teeth, fish scales, and the tritylodont Stereognathus ooliticus are among the most common identifiable fossils encountered. The teeth of several taxa of theropod and ornithischian dinosaurs are recognized, as well three pterosaur taxa, numerous other reptiles, multiple amphibians, three shark species, and more. Notably, a dozen mammal teeth have been identified as belonging to various different families. Many of the taxa identified are potentially new species, and call for further specialist attention.
1 - plesiosaur.com 2 - Hills Quarry Products Ltd 3 - Science and Technology Facilities Council
The excavations at Cerney Wick have been carried out over several years, and have been the subject of a lot of media attention. This year has been exceptionally successful both in terms of adding to the experience of many students and volunteers, and the potential for a number of research projects based on the findings from the site. The excavation ended at the beginning of August, so this is a preliminary account of the outcome and the future potential for this extraordinary locality.
1 - School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, BS8 1TQ, Bristol, United Kingdom 2 - Programa de Pós-graduação em Biodiversidade Animal, Universidade Federal de Santa Maria, Avenida Roraima 1000, 97105-900, Santa Maria, Rio Grande do Sul, Brazil 3 - Centro de Apoio à Pesquisa Paleontológica da Quarta Colônia, Universidade Federal de Santa Maria, Rua Maximiliano Vizzotto 598, 97230-000, São João do Polêsine, Rio Grande do Sul, Brazil 4 - Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” - CONICET, Av. Ángel Gallardo 470, C1405DJR, Buenos Aires, Argentina
The presence of enlarged maxillary recesses is notable in some non-Mammaliaformes cynodonts, especially traversodontids. Given that cranial pneumatization can be related to several functional parameters, the aim of this study is to evaluate the biomechanical role of the maxillary recess of three South American Triassic traversodontids: Exaeretodon riograndensis, Siriusgnathus niemeyerorum, and Massetognathus pascuali. We scanned the skulls with computed tomography, reconstructed the adductor musculature and calculated the muscle force for each species. We conducted a Finite Element Analysis (FEA) in two models for each species: one normal and one with digitally filled maxillary recesses. The biomechanical efficiency was evaluated by comparing the Von Mises stress distribution and bite forces of the two models. The results show that the stress distribution is very similar in both models in the three species, with the region of the maxillary recess presenting a markedly low stress in both the normal and filled models. The bite force was also very similar, being slightly lower in the filled models. These results indicate that the presence of enlarged maxillary recesses in these traversodontids does not have a strong biomechanical effect, and that it occurs in a region of low stress where bone is possibly superfluous.
1 - University of Bristol
The late Eocene exposures of the Headon Hill Formation at Hordle Cliff, near Lymington, have produced a diverse assemblage of vertebrate remains representative of a coastal lacustrine/lagoonal system. Most studies concerning this locality have focused on mammalian and reptilian faunas of the Basal Mammal Bed. This study presents and details the micro-vertebrate assemblages from 6 vertebrate bearing horizons throughout the succession, providing implications for a rapidly changing palaeoenvironment and an insight into late Eocene ecosystem dynamics in the Solent Basin. Targeted sampling of vertebrate bearing units and an in-depth sedimentological assessment of each unit has been undertaken to understand the implications of sedimentology, and micro-vertebrate assemblages relative to palaeoenvironment. Results show a varied and everchanging vertebrate composition and taphonomic profile throughout the units studied, with major changes occurring between units attributed to freshwater lakes and units attributed to brackish lagoonal facies. These results provide many implications concerning the trends in micro-vertebrate occurrences within each unit. The representation of key vertebrate groups provides insights into the vertebrate communities, climatic conditions, and salinity profiles of the locality. The ever-changing taphonomic windows can be used to critically assess these results for potential biases.
1 - Department of Zoology, University of Cambridge
Living golden moles (Chrysochloridae) and tenrecs (Tenrecidae) are known for several molecular loci. A recent phylogenetic analysis supports well-resolved topology for extant tenrecids and most chrysochlorids . However, currently available molecular data do not resolve the oldest branching point, or root node, within crown C hrysochlorid ae . Most of the hard-tissue anatomy of chrysochlorids has been indelibly stamped with their fossorial (i.e., burrowing) nature, making it difficult to reconstruct the mosaic pattern of evolution by which chrysochlorids evolved from a non-fossorial ancestor. Nonetheless , a surprising part of the chrysochlorid skeleton provides a hint as to the group's origins : the hyoid apparatus. In most species, the stylohyoid is "L" shape d with a bulbous distal end that articul ates with the dentary. The only extant chrysochlorids with a more primitive stylohyoid are Eremitalpa and Huetia , two of the prime candidates to occupy the group's root node . T he hyoid of the anatomically best-known fossil golden mole (Namachloris from Namibia) remains unknown, but its dentary angular process suggests that it too possessed a more primitive stylohyoid, without a jaw articulation . Hence, the oldest divergence(s) within Chrysochloridae is likely defined by one or more node s separating Eremitalpa and Huetia from the remaining species. (Available for virtual talk only)
1 - University of York 2 - University of Southampton 3 - Natural History Museum 4 - Unidad Ejecutora Lillo 5 - Hastings Museum and Art Gallery
The Lower Cretaceous Wealden Supergroup of southern England yields a diverse assemblage of theropod dinosaurs, its taxa being represented by fragments in addition to some of the most informative associated skeletons of the European Mesozoic. Spinosaurids, neovenatorid allosauroids, tyrannosauroids and dromaeosaurids are among reported Wealden Supergroup clades. However, the majority of relevant specimens are from the Barremian Upper Weald Clay and Wessex formations, and theropod diversity in the older Berriasian—Valanginian Hastings Group has remained poorly known, the fragmentary specimens reported thus far remaining enigmatic both in terms of phylogenetic affinities and sometimes provenance. A better understanding would be welcome given the paucity of Berriasian—Valanginian dinosaurs worldwide. Here, we describe an assemblage of Hastings Group theropod teeth from Valanginian Wadhurst Clay Formation outcrops of the Ashdown Brickworks locality near Bexhill, East Sussex. We subjected these teeth to phylogenetic, discriminant and machine learning analyses and found them to include members of Spinosauridae, Tyrannosauroidea and Dromaeosauridae, in addition to others that remain of uncertain affinity within Coelurosauria. Combined with other findings in the Wadhurst Clay Formation, our study indicates that Valanginian theropod diversity was comparable to that of younger Wealden Supergroup units, implying that the “characteristic” theropod components of Wealden faunas were established early within the deposition of this famous geological succession.
1 - Earth and Environmental Sciences, Katholieke Universiteit Leuven, Celestijnenlaan 200E, 3001, Leuven, Belgium 2 - Directorate Earth and History of Life, Royal Belgian Institute of Natural sciences, Vautierstreet 29, 1000, Brussels, Belgium 3 - CR2P, Sorbonne Université, CRNS-MNHN-Sorbonne Université, 4 Place Jussieu, 75005, Paris, France 4 - Collections & Muséographie, Musée d’Histoire Naturelle de Lille, 23 Rue Gosselet, 59000, Lille, France
Few groups are as controversial in current eusuchian systematics as the “thoracosaurs”. Occurring from Late Cretaceous through middle to late Eocene deposits of the northern hemisphere, these longirostrine crocodyliforms were long thought to be gavialoids, closely related to the extant Gavialis gangeticus. However, this contradicts most molecular clock estimates of a split between Gavialis and its extant sister taxon Tomistoma around the Oligocene – early Miocene. Moreover, the position of “thoracosaurs” varies between phylogenetic studies, from being the sister taxon of the extant Gavialis to being excluded from the crown group Crocodylia entirely. Despite these issues, “thoracosaurs” have received little attention from researchers in recent years. Here, we provide a comprehensive overview of the fossil record of this group, highlighting their diversity and widespread geographic distribution. Furthermore, we present new results of phylogenetic analyses with updated scorings based on new material of the key taxon Thoracosaurus isorhynchus from the Maastrichtian of the Paris Basin. Our findings indicate a close relationship between this taxon and the Cenomanian Portugalosuchus azenhae. The inclusion of the latter in “thoracosaurs” underlines the early emergence of this group and of gavialoids in general.
No abstract
1 - ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology 2 - Faculty of Geology and Geophysics, University of Bucharest 3 - ELTE Eötvös Loránd University, Faculty of Informatics, Institute of Cartography and Geoinformatics 4 - Hungarian Natural History Museum 5 - Supervisory Authority for Regulatory Affairs, Geological Survey, Department of Collections 6 - Dipartimento di Scienze della Terra e dell’Ambiente, Università degli Studi di Pavia 7 - HUN-REN–MTM–ELTE Research Group for Paleontology
At the beginning of the 20th century, Ottokár Kadić discovered a rich and diverse Late Cretaceous vertebrate assemblage around the village of Vălioara in the Haţeg Basin, including the types of the dwarf sauropod Magyarosaurus and the crocodyliform Allodaposuchus. Unfortunately, the actual positions of Kadić’s localities were not published and the stratigraphic and palaeoenvironmental setting of the Vălioara assemblages remained unknown. However, an unpublished map used by Kadić during fieldwork was brought to our attention in 2018 and was used to approximate the locations of the original sites. Since 2019, systematic excavations have been carried out in the area annually, resulting in the discovery of significant new vertebrate material from several different sites (including new ones), among which sites K2, NVS, and FNS are considered the most productive so far. Besides important isolated elements of crocodyliforms, theropods, pterosaurs and mammals, associated skeletons of rhabdodontid, titanosaurian and hadrosauroid dinosaurs were unearthed at these sites. Our stratigraphical and sedimentological investigations conducted in the area indicate that the Vălioara material represents the oldest systematically collected latest Cretaceous faunal assemblage from the Haţeg Basin. According to our results, these continental beds represent a sequence of syn-tectonic sediments deposited in an elongated transtensional strike-slip basin.
1 - University College London 2 - Royal Belgian Institute of Natural Sciences 3 - KU Leuven 4 - Universite Claude Bernard Lyon 1
Gavialoid crocodylians are represented by two extant species from southeast Asia, Gavialis gangeticus and Tomistoma schlegelii, which are restricted to freshwater environments and lack the ability for salt excretion. By contrast, their 80-million-year fossil record documents a cosmopolitan distribution, including occurrences recovered from shallow marine deposits. Furthermore, phylogenetic analyses recover closely related gavialoid species from either side of the Atlantic Ocean. All this evidence points to extinct gavialoids being capable of transoceanic dispersal but clear morphological features to support this hypothesis have yet to be documented. Based on CT scan data, we reconstructed the internal cranial anatomy of several extinct gavialoids. This reveals several lines of evidence that support a capability for transoceanic dispersal. Most notably, we identify concave depressions on the internal surface of the prefrontals and lacrimals, where the paranasal sinus expands, in the Late Cretaceous-Paleocene gavialoid taxa Eosuchus and Portugalosuchus. In extant seabirds and marine reptiles, these concave depressions are osteological correlates for nasal salt glands. They have also been noted and interpreted as such in thalattosuchian crocodyliforms, for which marine lifestyle is unequivocal. Our preliminary conclusions suggest the capacity for salt excretion and therefore transoceanic dispersal might be ancestral for Gavialoidea.
1 - University of Birmingham 2 - Natural England
Fossil tracks are a key means of determining the palaeoecology and distribution of dinosaurs through time and complementary to the skeletal record. They are also amongst the most popular and recognisable trace fossils encountered by the public and are major draw to some areas of the UK. Thus, beyond scientific value, they provide key aesthetic and pedagogic opportunities in the tourism and education sectors. However, the protection, monitoring, communication, and scientific knowledge of dinosaur track sites varies considerably. We reviewed the fourteen in-situ dinosaur track sites present in the UK today and used an established quantitative system to determine the relative scientific and cultural ‘value’ of each. We find that UK track sites vary substantially in scientific and cultural value, with some sites such as Ardley and Bendrick Rocks having high scientific value, whereas sites such as Hanover Point and Spyway have high cultural but low scientific value. We identified inconsistent documentation of sites with substantial knowledge gaps. Ultimately, dinosaur track sites are an important part of the UK’s heritage with strong potential to expand our knowledge of past ecosystems and engage the public, and ensuring appropriate protection, regulation and communication of this finite natural resource is important.
1 - University of Birmingham 2 - Indian Institute of Technology Bhubaneswar 3 - Panjab University, Chandigarh
Palaeoclimate from the Miocene of western India is well defined by vertebrates like crocodiles and shark fossils from the Kutch region. A ferruginous conglomerate bed from Samda in Kutch revealed heavily broken crocodilian remains. A partial skull of an unknown crocodilian (KF-40) was recovered between 2010 and 2011, and was initially thought to be a tomistomine (false gharial). The skull fragment (KF-40) consisted only of the anterior portion, the snout. It was diagnosed as a tomistomine due to its premaxillary-maxillary sutures and maxillary alveolar characteristics. However, in 2024, reexamination with more comparative analysis demonstrated the snout is more closely related to the family Crocodylidae rather than Tomistominae from the Gavialidae family. The suture pattern from the dorsal and ventral sides along with the dentition pattern strongly suggests the specimen is from the Crocodylidae family. The premaxillary-maxillary suture with the absence of nasal suture proximate to the naris along with the massive naris and broad snout resembles the extinct crocodylomorph group Pholidosauridae, which includes the giant Sarcosuchus imperator. The group Pholidosauridae ranges from the Jurassic to the Late Cretaceous; therefore, the morphology of KF-40 is a result of convergent evolution. The estimated size of the skull based on the snout could potentially rival Sarcosuchus imperator in skull length. Complete crocodilian fossil specimens with proper identification and taxonomy in South Asia are scarce and understudied, often with dubious taxonomy. This redescription provides a more accurate identification and can further our understanding of crocodilian diversity, evolutionary relationships, and wider faunal migratory routes in response to climate change.
1 - Staatliches Museum fur Naturkunde Stuttgart
Pelagic suspension-feeding has independently evolved many times in vertebrates. Pachycormiforms is an important clade of marine stem-teleosts which include some of the earliest know vertebrate suspension-feeders. Inferences for this ecology in large-bodied asthenocormine pachycormids, including Leedsichthys and Asthenocormus from the Upper Jurassic, are based on the presence of elongate toothless jaws and modified gill rakers in the gill arches. However, very little is known of the anatomical origins and causation for the acquisition of this feeding strategy within the clade. A review of ‘suspension-feeding’ characteristics in Lower Jurassic asthenocormine pachycormids with transitional morphologies reveals a wealth of vital clues to piece together this evolutionary enigma. Key anatomical landmarks in Saurostomus, Germanostomus, Ohmdenia, and an undescribed taxon, offer insight into the timings and order of acquisition for these key features. These include reduced cranial ossification, progressive jaw elongation, modification to the hyomandibula, tooth reduction, and specializations in the caudal fin. Surprisingly, the loss of tooth is only first detected in the Middle Jurassic. Examination of preserved gut contents suggests these anatomical changes in pachycormids are associated with a dietary shift from raptorial macrophagy to bulk-feeding. Identification of piscivorous gut contents in Late Jurassic asthenocormines sheds doubt on their supposed ‘suspension-feeding’ ecologies.
1 - University of Bath 2 - TotalSim CFD Ltd
Hagfishes, one of the only two surviving lineages of jawless fishes, occupy an important basal phylogenetic position in vertebrate evolution. There is, however, a paucity of information on their sensory biology. One interesting question regarding the olfactory ability of the monorhinal hagfishes is how they find the source of a scent with just a single nostril. We have answered this question by performing computational fluid dynamics on an anatomically accurate model of the head and nasal passage of the hagfish Eptatretus stoutii. We will present the answer here. We will also show how the hagfish’s anatomy controls the flow of water through its nose to help it capture scent molecules, whilst simultaneously avoiding damage to its delicate nasal surfaces. In addition, we will present quantitative data showing how the hagfish’s sense of smell squares up to that of dogs. Our results are relevant to olfaction in other early monorhinal vertebrates, both living (lampreys - the other surviving lineage of jawless fishes) and dead (osteostracans, a group of ostracoderms). Consequently, we hope that this talk will appeal to the attendees of the annual Symposium of Vertebrate Palaeontology and Comparative Anatomy.
1 - University of Manchester 2 - University of Liverpool
The fossil record cannot preserve the dynamics of animal locomotion, such as kinematics or reaction forces, and the only way to systematically reconstruct these features is through simulation. However, simulating the movement of fossil taxa presents numerous challenges, not least because of the absence of fundamental soft-tissue information. Here, we perform a sensitivity analysis of predicted maximum-effort vertical jumping performance – an important motion in the locomotor repertoire of many animals – by treating two living taxa with reliable experimental data (humans and guineafowl) as if they were extinct. We show that when known muscle properties are used alongside common modelling techniques, simulated maximum jump heights are within 15% of the experimental average of both taxa across several distinct starting postures and jumping techniques. However, when muscle masses are estimated using the schematic and predictive methodologies usually applied to fossils, large differences in the power available to the model and therefore overall jumping performance can be produced. That said, even substantial over- and underestimations of muscle mass will generally uphold qualitative differences in jumping between starting postures, which we suggest validates this workflow, with specific caveats, for evolutionary analyses where broad changes in body shape and posture may significantly impact vertical jumping.
1 - Department of Musculoskeletal & Ageing Science, University of Liverpool 2 - Department of Earth Sciences, The Natural History Museum 3 - Department of Earth Sciences, Utrecht University 4 - Vertebrate evolution, development and ecology, Naturalis Biodiversity Center 5 - School of Geography, Earth and Environmental Sciences, University of Birmingham
Among large quadrupedal dinosaurs, the armoured ornithischian Stegosaurus has distinctive body proportions, including its long femur, short humerus, and broad pelvis. The influence of body shape on the locomotor biomechanics of Stegosaurus is therefore a topic of particular interest. Here, we present our workflow and preliminary results from a new biomechanical model of Stegosaurus, based on the exceptionally complete “Sophie” skeleton (NHMUK PV R36730), and constructed for use in the musculoskeletal simulation software OpenSim. To ensure that the estimated soft tissue parameters were empirically grounded, body segment and muscle dimensions were based on soft tissue scaling factors derived from extant sauropsids. We predict a body mass of 1.6 tonnes, with the combined muscle masses of all four limbs making up 19% total mass. Compared to large mammals and predicted values from other quadrupedal dinosaurs, a greater proportion of this predicted muscle mass belongs to the hind limbs in Stegosaurus (forelimb/hind limb muscle mass = 0.40 in Stegosaurus, compared to 0.64 in Chasmosaurus, 0.55 in Rangifer, and 0.91 in Rhinoceros). This, in addition to a relatively posterior centre of mass, may suggest that the hind limbs of Stegosaurus played a greater role in weight bearing and propulsion than other quadrupeds.
1 - Centre for Integrative Anatomy, Department of Cell and Developmental Biology, University College London, London, UK 2 - Palaeobiology Research Group, School of Earth Sciences, University of Bristol, Bristol, UK 3 - European Synchrotron Radiation Facility, Grenoble, France 4 - Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, MD, USA
Lungfishes are the first vertebrate lineage that evolved durophagy. This ability to eat hard prey entails a series of anatomical specialisations compared to the ancestral sarcopterygian morphotype. The sequence of the morphological transformations associated with durophagy is now better understood, but their significance for skull biomechanics remains unclear. Filling this gap requires a detailed appraisal of the feeding system mechanics in living lungfishes. We here compare the musculoskeletal anatomy and mechanical behaviour of the mandible of the Australian (Neoceratodus) and the African (Protopterus) lungfish. Quantitative dissections and 3D reconstructions from high-resolution synchrotron scans revealed clear differences in the morphology of the jaw-closing muscles between the two species. The jaw-closing muscles of the African lungfish are more vertically oriented and have a greater physiological cross-section area. Musculoskeletal modelling shows that the feeding system of the African lungfish generates higher bite force, and is more efficient in transmitting muscle force and minimizing joint-reaction force during biting. Finally, finite element analysis reveals that the distinct loading regime of the mandible in the two species results in distinct deformation regimes, bone strain magnitudes and distribution. This study lays the foundation for a broader comparative study of cranial biomechanics in extant and fossil lungfishes.
1 - National Museums Scotland 2 - University of Edinburgh 3 - Manchester Metropolitan University 4 - Univeristy of Manchester
Nocturnal, arboreal and aquatic mammals are classed as whisker specialists due to their organised vibrissae and crucial role they play in sensory ecology. Pinnipeds, like seals, possess long, organised, sensitive mystacial vibrissae that are highly mobile, essential for underwater foraging and navigation. Traditional histology, offering two-dimensional images, limits our understanding of these complex structures, especially given the large, curved mystacial pad of pinnipeds. Unlike rodents, the vibrissal muscles of pinnipeds remain largely unexplored. In rats and mice, intrinsic muscles in the mystacial pad protract the vibrissae during sensory exploration. Therefore, we predicted harbour seals, would possess regular, well-defined intrinsic muscles due to their organised vibrissae and underwater foraging in dark environments. Using diffusible iodine contrast-enhanced computed tomography (diceCT), we described for the first time, the three-dimensional architecture of harbour seal mystacial pads. Contrary to our expectations, the intrinsic muscles were not well-defined, but were regularly distributed. Additionally, we identified several large, deep extrinsic muscles extending throughout the pad, suggesting these muscles play a key role in driving vibrissal protraction underwater, unlike in rats and mice. These findings highlight the value of three-dimensional visualisation techniques in understanding the complexities of pinniped mystacial anatomy and function, offering new insights into their sensory system of pinnipeds.
1 - Manchester Metropolitan University
Pinnipeds possess long, sensitive, moveable mystacial vibrissae. In other mammals vibrissae are protracted by intrinsic muscles within the mystaicl pad. The mystacial muscles of pinnipeds have not been systematically described, compared to other whisker speiclists such as rats and mice. Traditional histology provides only two-dimensional images, limiting understanding, especially given the large curved mystacial pads of pinnipeds. We predicted that harbor seals would have regular, well-defined intrinsic muscles due to their moveable organsised vibrissae. Using diffusible iodine contrast-enhanced computed tomography (diceCT), we described the three-dimensional architecture of harbor seal mystacial vibrissal muscles for the first time. Our observations revealed that the vibrissae are organised into a grid like pattern within the mystacial pad. We identified sling-shaped and oblique intrinsic muscles connecting vibrissae in the same row. Additionally, extrinsic muscles such as the m. nasolabialis (NL), m. maxillolabialis (ML), m. lateralis nasi, and m. orbicularis oris were identified. Contrary to our prediction, intrinsic muscles were not well-defined but regularly distributed. In contrast, the extrinsic muscles, particularly the NL and ML, were large, deep, and well-defined, extending throughout the mystacial pad. We suggest these large extrinsic muscles drive vibrissal protraction underwater. These findings highlight the value of three-dimensional visualization techniques in understanding pinniped mystacial anatomy and function.
1 - Steve Etches Museum 2 - Chris Moore Fossils
A film about the discovery of a huge pliosaur from the Kimmeridge Clay
1 - University of Reading 2 - University of Lincoln 3 - University of St Andrews
Bipedal locomotion is a cornerstone of hominin evolution. Many studies have estimated the costs of walking and running in select hominins; however, it remains untested whether locomotor costs decreased over time. Here, we apply phylogenetic comparative methods to biophysical models of bipedal walking and synthesise estimates on locomotor costs with morphologies commonly linked to efficient bipedal movement. We leverage data from over 450 hominoid fossils to make phylogenetically informed predictions about lower limb length, stature, and body mass for 25 extinct hominoid species. When available, we also collected data on the presence of characters linked to efficient bipedal locomotion. We then used a Bayesian phylogenetic generalised linear mixed model to test for general trends in lower limb length, stature, body mass, and the mechanical and metabolic costs of walking through time. The model accounts for uncertainties in our predictions, fossil age ranges, taxonomic assignments, and phylogenetic topology. We also test for trends in locomotor costs within species and examine potential deviations from an overall trend. Future analyses will test for an association between locomotor costs, brain size evolution, and palaeoenvironmental change. The study sets a benchmark for future studies on biomechanical evolution that applies to many terrestrial vertebrate clades.
1 - University of Bristol 2 - University College London 3 - Université de Bordeaux
Salamanders are often used as modern analogues to study the evolution of functional traits across the fish-tetrapod transition. Recent research has demonstrated that the diversity of salamander feeding mechanisms has been underappreciated, and a paucity of knowledge surrounds the function of their mandibles. We address this knowledge gap by studying the structural performance of the mandibles of seven species that represent several major salamander clades. High-resolution 3D finite element models of the mandibles were generated from micro-CT and synchrotron acquisitions. Jaw adductor muscle mass and architecture were collected from dissections to estimate muscle force, which was used to load the FE models. Although strain distribution patterns were generally similar between taxa, strain gradients and magnitudes were influenced by the relative size, shape, and dimension of the Meckel’s cartilage. Mandibles with proportionally large cartilaginous contributions exhibited substantially greater strain magnitudes than those with smaller cartilaginous contributions. Since early tetrapods are inferred to have proportionally smaller cartilaginous contributions to the mandible than most extant salamanders, we suggest that the use of salamanders as analogues has underestimated the structural performance of early tetrapod mandibles, obscuring our understanding of the capacity for early tetrapods to adapt to feeding out of water by biting.
1 - Manchester Metropolitan University
Most mammals have whiskers to feel around their environment. Whisker deformations, following a contact, will be felt within whisker follicles and translated into neural signals. How much the whisker bends will depend on its shape and material. However, it is hard to understand how whiskers bend, since they are small and flexible and have complex shapes. It is also challenging to measure their material properties. Here, we adopt finite element modelling to explore how shape affects whisker bending in three Carnivora species - a terrestrial red fox (Vulpes vulpes), semi-aquatic Eurasian otter (Lutra lutra) and aquatic grey seal (Halichoerus grypus). We present novel methods to select whiskers and approximate their shape and material stiffness. Using our approach, we show that taper (in all species) and undulations (found only in seal whiskers) can both contribute to making whiskers bend more. We also show that the aquatic species have stiffer whiskers than the terrestrial fox – which helps them to keep their whiskers positioned precisely underwater. Overall, we make recommendations here for studying whisker biomechanics, especially to help us understand more about whisker bending and the resulting sensations.
1 - Royal Tyrrell Museum of Palaeontology
Gastroliths from four Alberta (Canada) plesiosaurs were studied to determine both their shapes and masses, and their mass fractions relative to body mass. One animal’s set of gastroliths was 100% complete and fully visible, but the others showed varying degrees of loss, damage or obscuration, so estimations of their original states were needed. The studied animals were: Albertonectes vanderveldei, Fluvionectes sloanae, Nichollssaura borealis and Wapuskanectes betsynichollsae. The animals come from three different palaeoenvironments: open marine, near shore marine, and fluvial. Gastrolith shapes were classified as either xiphoid, cylindrical, discoidal or spherical based on observed and/or estimated dimensions. Total gastrolith mass never exceeded 0.2% of body mass in any plesiosaur, and is consistent with the idea that the amounts of gastroliths recovered with plesiosaurs would be ineffective as ballast. The largest plesiosaur in the sample had the largest single gastrolith and total gastrolith mass increases with body size. The shape characteristics of the gastroliths were different for different environments, but compositionally they are dominated by black cherts. A possible common source for the gastroliths was identified for the two geographically close and near-contemporanous Nichollssaura and Wapuskanectes.
1 - 71, Hoppers Road, London N21 3LP 2 - None
1 - ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Physical Geography, Pázmány Péter sétány 1/C, Budapest 1117, Hungary 2 - 901 route du village 04290 Salignac, France 3 - Centre de Recherches en Paléontologie – Paris, UMR 7207, CNRS-MNHN-SU, Muséum National d’Histoire Naturelle, 8 Rue Buffon, CP38, 75005, Paris, France 4 - ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology, Pázmány Péter sétány 1/C, Budapest 1117, Hungary
The Lower Cretaceous European ankylosaur record is very poor, and species-level forms are known only from England and Spain. Here we present an associated ankylosaur specimen from the Lower Cretaceous (Albian) marine beds of southeastern France. The partial skeleton consists of several hundred bone elements, in which most of the vertebral column and rib cage, elements of the pelvic girdle and limbs, and most of the armour are preserved, but a significant part of the bones have suffered severe bioerosion.
Our phylogenetic analyses recovered the new ankylosaur as a member of Struthiosauridae sensu Raven et al. 2023, being the sister taxon of a derived clade containing e.g. Europelta, Borealopelta, Hungarosaurus, and Tianchisaurus. This placement is supported by the fusion of the pubis to the ilium and ischium, a humeral head separated from the deltopectoral crest and medial tubercle, and heart-shaped anterior caudal vertebrae.
As well as helping to better understand the diversity of European anklyosaurs and to elucidate more precise relationships between Cretaceous forms, this find is the most eastern diagnostic occurrence of the group on the continent. In addition, it further increases the number of ankylosaurian finds from sedimentary rocks formed in nearshore or marine environments.
1 - Natural History Museum, London, UK 2 - University of Portsmouth
The Early Cretaceous Wessex Formation, Wealden Group, of the Isle of Wight, UK, is a series of fluvial sandstones and floodplain clays, which yield a high diversity of vertebrate remains, including dinosaurs. Commonly found amongst these remains and throughout the succession, are well-rounded exotic stones, exhibiting a high surface polish, with a unique surface texture that identifies them as gastroliths. Concentrations of these stones have also been found in association with sauropod remains. An analysis of 388 gastroliths, all discovered in situ within the Wessex Formation sediments, revealed a wide diversity of lithologies including chert, silicified limestone and wood, sandstone and various metamorphic rocks. The sources of these gastroliths were investigated using petrography and fossil content and revealed two major provenances: 1. relatively locally derived (within 50 km) silicified Jurassic limestones and cherts, and 2. orthoquartzite and metamorphic clasts derived from Triassic conglomerates in Devon, some 150-200 km to the south west. Other than in gastroliths these lithologies do not occur in the Wessex Formation of the Isle of Wight and are not represented in Brittany and France to the south and east.
The results indicate that dinosaurs, most likely sauropods, were responsible for their transport and that the acquisition of the stones involved travel over considerable distances, to access two individual source areas. Although the primary reasons for visiting these sites are unknown, it may be linked to seasonal migratory routes or topographical constraints. This implies that the sauropod’s choice of gastroliths could have been highly selective and even indicative of complex patterns of learnt behaviour.
Preliminary experiments to replicate the polish using a rock tumbler and a mix of Equisetum, pine needles, water and pebbles with a lithology typical of the study gastroliths, demonstrate an effective maceration process. Contrary to previous studies, the diagnostic polish of gastroliths could be achieved in a couple of weeks.
This study provides new evidence that gastroliths from the Early Cretaceous sediments of the Wessex Formation were transported by dinosaurs and in this case were acquired from two specific localities.
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1 - University of Bristol 2 - American Museum of Natural History 3 - Institute of Vertebrate Paleontology and Paleoanthropology 4 - Marian University 5 - Fukui Prefectural University 6 - Fukui Prefectural Dinosaur Museum 7 - Ohio University Heritage College of Osteopathic Medicine 8 - Ohio Center for Ecology and Evolutionary Studies 9 - Shandong University of Science and Technology
Extant birds possess highly encephalized brains that evolved from non-avian dinosaur ancestors. Evolutionary shifts in developmental timing, namely juvenilization of adult phenotypes, have been proposed as a driver of head evolution along the dinosaur-bird transition, including brain morphology. Testing this hypothesis requires a sufficient developmental sampling of brain morphology in non-avian dinosaurs. In this study, we harness brain endocasts of a postnatal growth series of the ornithischian dinosaur Psittacosaurus and several other immature and mature non-avian dinosaurs to investigate how evolutionary changes to brain development are implicated in the origin of the avian brain. Using three-dimensional characterization of neuroanatomical shape across archosaur reptiles, we demonstrate that the brain of non-avian dinosaurs underwent a distinct developmental trajectory compared to alligators and crown birds; both ornithischian and non-avialan theropod dinosaurs shared a similar developmental trajectory, suggesting that their derived trajectory evolved in their common ancestor; and the evolutionary shift in developmental trajectories is partly consistent with paedomorphosis underlying overall brain shape evolution along the dinosaur-bird transition; however, the heterochronic signal is not uniform across time and neuroanatomical region suggesting a highly mosaic acquisition of the avian brain form.
1 - University of Manchester
The contribution of social and ecological factors to the evolution of large and complex brains in mammals is widely acknowledged. Despite numerous comparative studies on the impact of these variables on brain size, a comprehensive framework for understanding their relationship with brain shape is lacking. Here, I employ landmark-based 3D geometric morphometrics to investigate the impact of phylogeny, allometry, ecology, and sociality on brain shape within Caniformia (Carnivora). Using phylogenetic comparative methods, I test two key hypotheses: 1) brain shape varies between social and non-social species due to the cognitive demands of social environments (the ‘social brain hypothesis’), and 2) brain shape varies between ecological groups due to the specialized motor and sensory demands of each lifestyle. Preliminary work on the superfamily Musteloidea revealed distinctive brain morphologies across different families and subfamilies, particularly the subfamily Lutrinae (otters), which possess traits well-adapted to aquatic life. With the inclusion of a broader sample of carnivores, including semi-aquatic families (pinnipeds), I examine the impact of terrestrial and semi-aquatic lifestyles on brain shape evolution in Caniformia. This study aims to disentangle the impact of ecology and phylogeny on brain shape while testing for convergent evolution in brain shape between carnivore groups with similar lifestyles.
1 - University of Bristol
The general assumption is that survivors of mass extinctions show a reduction in body size, the Lilliput Effect, but then may diversify fast, according to the 'early burst' (EB) evolutionary model. Global ecosystems were obliterated in the Permian-Triassic mass extinction (PTME) by extreme volcanism which triggered numerous killing mechanisms and eradicated 90% of life. Amongst the ashes, a few resilient lineages survived, and their struggle for ecological dominion shaped the structure of modern ecosystems. Here, we test whether the survivors among Actinopterygii and Tetrapoda (Cynodontia, Dicynodontia, Therocephalia, Temonspondyli, and Procolophonidae) show evidence for the Lilliput Effect and their evolutionary models following the PTME. Body size did not appear to govern the survivorship of actinopterygians, dicynodonts, and procolophonids, however, size reductions are observed amongst the cynodonts, temnospondyls, and therocephalians. Neopterygians exhibit a low phylogenetic signal, which may reflect prolific diversification as part of the Mesozoic Marine Revolution. Temnospondyls and dicynodonts follow an EB pattern but their rates and occurrences continually declined through the Triassic, whereas therocephalian and procolophonid body size evolution follow both punctuated and constrained models. The cynodonts show no overall pattern, but their two major subgroups (Gomphodontia and Probainognathia) appear to show opposite trends (size increasing and decreasing respectively).
1 - Royal Veterinary College 2 - University College London 3 - KU Leuven
Terrestrial animals not only need to walk and run but also lie prone to rest and then stand up. The sit-to-stand (STS) transition likely imposes biomechanical constraints on limb design because it involves near-maximal excursions of some limb joints. Birds, a diverse lineage of bipedal animals with exceptional locomotor agility, provide a valuable opportunity to study STS biomechanics and the impact of body size on performance. However, experimental investigation is typically limited in revealing fundamental mechanisms. Using computational biomechanical models and predictive simulations, we can explore the questions on STS performance criteria, muscle-tendon dynamics, and body size influence in a detailed and mechanistic way. In this study, we used a combination of a 2D simplified model and a 3D high-fidelity musculoskeletal model to evaluate STS performance criteria (e.g., minimisation of effort and force rate) and estimate muscle functions in a large bipedal bird – the emu (Dromaius novaehollandiae), with future investigations extending to simulate STS in a smaller bird – the common pheasant (Phasianus colchicus). Our study provides insights into the control strategies used by these avian species during STS and suggests the influence of anatomical and functional traits on STS performance. These findings enhance our understanding of constraints on muscle structure in extant animals and offer valuable implications for reconstructing musculoskeletal function in extinct species.
1 - University College London 2 - Natural History Museum 3 - Yale University 4 - UCL and NHM 5 - University of Huddersfield 6 - Universität Zürich 7 - University of Aberdeen
The presence of numerous sympatric medium- to large-bodied theropod dinosaurs in the Morrison and Bahariya Formations raises questions regarding levels of inter- and intraspecific competition and its effect on community structure. Dietary niche partitioning may decrease competition intensity but constraining dinosaur diets has often relied on tooth morphology and stomach contents, both of which have limitations. Here, we use 3D dental microwear texture analysis (DMTA) to constrain the diets of 15 species across all dentulous neotheropod clades, in comparison to extant crocodylians and varanids with known diets. We show evidence for piscivory in , and possible invertivory in Eotyrannus, suggesting that faunivorous theropod diets were more diverse than previously thought. Preliminary results suggest theropod clades exhibit different degrees of ontogenetic dietary shifts. Spinosaurid ontogenetic dietary shifts, for example, appear less pronounced than the distinct shifts inferred in . The statistically significant ontogenetic shifts in tyrannosaurid diets suggests these genera performed several distinct ecological roles during their life cycles which might have prevented the sympatry of other large-bodied theropods through competitive exclusion.
1 - Imperial College London
Our understanding of the swimming abilities of Mesozoic marine reptiles varies significantly among different groups. The swimming methods of certain groups such as ichthyosaurs are fairly well established due extensive research effort and straightforward comparisons to extant fauna. However, other groups such as the plesiosaurs and thalattosaurs have received less attention or are more challenging to interpret, leaving their swimming capabilities ambiguous. In this short review, the current state of knowledge regarding the hydrodynamics of Mesozoic marine reptiles is explored. The groups with well-established swimming methods are identified, the various locomotion techniques employed are described, the methodologies used to reach these conclusions are considered, and areas for future research are suggested.
1 - University of Tübingen 2 - University of Turin 3 - University of Lyon 4 - University of São Paulo
Species of the extinct ‘terror crocodile’, Deinosuchus, were among the largest crocodilians to ever live. Two of its roughly contemporaneous species differed in body size and geographic distribution with the smaller species limited east of the Late Cretaceous Western Interior Seaway of North America and the larger to the west. This biogeographic pattern together with a gigantic body size, specialised morphology, and evidence for a coastal habitat preference has been difficult to reconcile with the consistently inferred alligatorid phylogenetic affinities of Deinosuchus. Extant alligators and caimans lack lingual glands for saltwater tolerance, consistent with the distribution of other early relatives of Alligatoridae, otherwise small-sized and morphologically more similar to extant representatives of the group. We present an expanded phylogeny that finds that Deinosuchus was no “greater alligator” and reinterprets it as a stem-group crocodylian, along with Diplocynodon and Leidyosuchus canadensis. The novel topology implies saltwater tolerance in Deinosuchus and is consistent with divergence of Alligatoridae from other crocodylians driven by extreme sea level rise. Phylogenetic body-length analysis reveals size reduction early in alligatoroid evolution and a shorter, more reasonable total length estimate for Deinosuchus than previously inferred. We find that gigantism in crocodyliforms is strongly correlated with exceptional, high-productive aquatic or wetland ecosystems in the present and the past.
1 - University of Bristol
Abstract to come
1 - University College London 2 - Natural History Museum, London 3 - Museo Argentino de Ciencias Naturales 4 - University of Aberdeen 5 - Oklahoma State University, Tulsa Oklahoma 6 - Northern Arizona University 7 - Anglia Ruskin University, Essex 8 - University of Pittsburgh 9 - Brigham Young University, Utah 10 - University of Wyoming
Megaraptora is an enigmatic clade of coelurosaurian theropods, with a complicated phylogenetic history. Most modern analyses agree that megaraptorans are closely related to/nested within Tyrannosauroidea. Recent studies in megaraptoran phylogenetics allow for detailed study of macroevolutionary patterns within Megaraptora. Here, we use BioGeoBEARS to conduct rigorous biogeographical analyses of Tyrannosauroidea, in order to provide insight into the processes which drove tyrannosauroid biogeography and to elucidate the origins of, and dispersal routes for, key megaraptoran lineages. We demonstrate that tyrannosauroid biogeography is governed by subset sympatry of widespread ancestral stocks, regional population extinction and jump dispersal. Regardless of their placement within Tyrannosauroidea, megaraptorans likely originated in Asia during the Middle Jurassic–Early Cretaceous (170–130 Ma) and dispersed to Gondwana through Europe, Africa and Antarctica, reaching Australia as early as the Late Barremian–Early Aptian. Distinct Australian and South American megaraptoran lineages are likely the result of Gondwanan break-up and vicariance resulting in the isolation of widespread non-megaraptorid and megaraptorid megaraptoran populations. We recognise convergent trends towards gigantism (≥1000 kg; +8m length) in three disparate tyrannosauroid lineages, with the onset in eutyrannosaurians and megaraptorids concomitant with the Cenomanian–Turonian boundary and the extinction of carcharodontosaurids. This association was a probable driver of tyrannosauroid gigantism.
1 - University of Bristol
Dinosaurs exhibited numerous dietary adaptations, enabling them to occupy a wide array of ecological niches throughout their dominance. Many of these adaptations originated during their initial radiation from the late Triassic (237-227 Ma) and are often linked to their dentitions. Historically, the feeding habits of dinosaurs have been hypothesised from morphological studies in comparison with extant analogues to infer dental function.
However, these methods lack biomechanical evaluation and have yet to quantify the tooth mechanics involved during feeding. Here, we use a combined approach of finite element analysis of tooth function alongside physical puncture tests to investigate tooth mechanics and food-tooth interactions during feeding in early dinosaurs. Our analyses use idealised models representative of the three tooth types seen in early ornithischians, sauropodomorphs and theropods. Results from biomechanical testing show sauropodomorph teeth exhibiting poor structural strength supporting their primary diet of soft plants. Ornithischian teeth demonstrated high structural strength and low puncture performance, supporting hypotheses of prioritising tough plant material. Theropod teeth perform best during puncture and slicing tests within specific contact angles. Dental adaptations of early dinosaurs were immensely varied and more nuanced than previously theorised which is indicated by testing functional hypotheses through these biomechanical analyses.
1 - University of Bristol
Dinosaurs exhibited numerous dietary adaptations, enabling them to occupy a wide array of ecological niches throughout their dominance. Many of these adaptations originated during their initial radiation from the late Triassic (237-227 Ma) and are often linked to their dentitions. Historically, the feeding habits of dinosaurs have been hypothesised from morphological studies in comparison with extant analogues to infer dental function.
However, these methods lack biomechanical evaluation and have yet to quantify the tooth mechanics involved during feeding. Here, we use a combined approach of finite element analysis of tooth function alongside physical puncture tests to investigate tooth mechanics and food-tooth interactions during feeding in early dinosaurs. Our analyses use idealised models representative of the three tooth types seen in early ornithischians, sauropodomorphs and theropods. Results from biomechanical testing show sauropodomorph teeth exhibiting poor structural strength supporting their primary diet of soft plants. Ornithischian teeth demonstrated high structural strength and low puncture performance, supporting hypotheses of prioritising tough plant material. Theropod teeth perform best during puncture and slicing tests within specific contact angles. Dental adaptations of early dinosaurs were immensely varied and more nuanced than previously theorised which is indicated by testing functional hypotheses through these biomechanical analyses.
1 - University of Leicester
The Solnhofen plattenkalks have yielded the world’s most significant pterosaur assemblage, yet the taphonomic processes that consigned these animals to the fossil record remain poorly understood and underexplored. Multiple examples of catastrophic injuries, combined with a comprehensive quantitative approach to taphonomy, reveal the influence of two distinct taphonomic pathways.
The primary taphonomic pathway is indicated by complete and often fully articulated small- to medium-sized individuals, often exhibiting traces of soft tissue preservation and, in some cases, major traumas to limb bones that had fatal consequences. These individuals likely perished during storms, suffering wing failure due to excessive wing loading. The same storm events ensured rapid drowning/waterlogging in rough seas and swift burial in storm-driven muds.
In stark contrast, the remains of larger individuals are often disarticulated and incomplete. These partial remains suggest a secondary attritional pathway involving extended periods of floating and drawn-out disintegration on the lagoon floor. Strongly right-skewed size distributions, along with higher degrees of articulation and completeness among smaller size classes, indicate that the catastrophic taphonomic mode is dominant in the Solnhofen assemblage. These findings highlight a significant ontogenetic bias: smaller individuals are overrepresented, while larger, mature individuals are largely absent from the record.
1 - University of Portsmouth
Extreme deep-diving, defined as movement to depths below the epipelagic zone, is a widespread behaviour among extant secondarily aquatic tetrapods. This behaviour is often used to access concentrations of prey that would otherwise be unavailable or to avoid predators. Ichthyosaurs, Mesozoic marine reptiles with extreme aquatic adaptations, have long been hypothesised to have engaged in deep-diving behaviour due to the extreme size of their orbits, evidence for diets of soft-bodied cephalopods and instances of avascular necrosis likely caused by decompression syndrome. Here, we investigate the ribcage morphology of ichthyosaurs and draw comparisons to the thorax anatomy of deep and shallow-diving cetaceans. Geometric morphometric techniques are applied to a dataset of cetacean skeletons to quantify the morphospace occupation of ribcages, and compared to linear measurements of ichthyosaur ribs from a wide range of taxa. A minimum of four ichthyosaur ribcage morphs are identified across sampled taxa, one of which is hypothesised to represent a specialised deep-diving morph. The Late Jurassic ophthalmosaurine Thalassodraco etchesi is found to be an exceptional taxon, with a relatively deep ribcage including some ribs nearing twice the length of the reconstructed skull. Combined with its unique dentition, this suggests a specialised lifestyle for this ichthyosaur that compels further investigation.
1 - University of Leicester 2 - Jura Museum, Eichstätt
Pterodactylus antiquus from the Upper Jurassic of Germany, the first pterosaur to be described, has been central to our understanding of these Mesozoic flyers. For many years knowledge of P. antiquus rested upon just five specimens. Recent taxonomic revision of this pterosaur has extended the hypodigm to 40+ individuals. Reinvestigation of 25 exceptionally well-preserved examples, using UV light photography, has revealed a wealth of new anatomical details such that our knowledge of soft tissue and skeletal anatomy for P. antiquus exceeds that for any other pterodactyloid pterosaur. This study confirms the presence of extensive flight surfaces including a cheiropatagium that reached to the ankle rather than the knee. A closely packed layer of aktinofibrils is present throughout the flight patagia. Aktinofibrils in the outer wing are elongate, remarkably straight and seemingly relatively stiff while those nearer the body are sinuous and more flexible. This study provides new insights into the development of aktinofibrils which scale from around 20µm in diameter in flaplings to 60µm, or more, in mature individuals. Other soft tissues include rhamphothecae, cranial crests, throat sacs, claw sheaths, foot webs, scales on the underside of the pes and an integument with a fine granular texture but no pycnofibres.
1 - The University of Manchester
Body mass relates to a wide range of factors in the ecology of animals, such as diet, predator-prey relationships, and locomotion. Therefore, rates and modes of evolution of body mass have been widely studied, especially in mammals. The predator-prey interactions of carnivores and artiodactyls may have affected their evolution. This biotic effect could be expressed in their diversification patterns or in their phenotypes, such as their body mass. This study explores rates and modes of body mass evolution in terrestrial Cetartiodactyla and carnivores (Carnivora, Hyaenodonta, Oxyaena). Large scale phylogenies with fossil tip data and inferred body masses, as well as diet, geographic location and global temperature were extracted from the literature and databases. Lineage and disparity through time, temperature correlations and analysis of the rates and modes of evolution show no direct correlation between carnivore and artiodactyl body mass but do hint at previously suggested patterns. Temperature has a large effect on body mass. Shifts in rate of body mass in both carnivores and artiodactyls appear to occur during temperature optima. There also is a significant effect of temperature on the number of carnivore lineages. These initial results suggest an important role for temperature in the evolution of these clades.
1 - University of Bristol
The fragmentary nature of pterosaur remains produces a dichotomy where, while much is known about their diversity, ecology and phylogeny, aspects of pterosaur morphology, particularly wing shape, remain controversial. In the absence of well-preserved stretched fossil wings, shape-based analyses of pterosaur flight are limited to linear measurements or reconstructed wing forms. Using theoretical morphospace analysis, we test whether published pterosaur reconstructions are useful as morphological proxies and whether artist style biases morphospace occupation. We create a theoretical space of all possible shape variation in the pterosaur wing, into which we project 91 modern wing reconstructions (since 2000) from 10 taxa to analyse their relative clustering and functional performance. We further examine whether the niche separation proposed for pterosaur groups using linear measurements is preserved, by comparing theoretical morphospace occupation of pterosaurs with that of extant birds. Our research indicates that reconstructions of pterosaur wings from the published literature do not function as living animals and exclusively occupy a thin-winged, soaring morphology. While individual artist style has little impact on wing efficacy, reconstructions are not a useful proxy for studying pterosaur flight.
1 - University of Manchester
Crocodylomorpha are a diverse group of Archosauria, and are thought to have first evolved during the Triassic period. They have achieved tremendous diversity, with body lengths ranging between 60 centimetres to over 10 metres , adapting to a range of diets and locomotor modes, and fossil evidence has been found all over the world. Despite their long evolutionary history, more recent taxa (100ma - present) have kept a similar fundamental body plan, generally displaying a large elongated skull, a flexible thoracic column, four phalanges on each limb, and a flexible elongated caudal spine, that is usually longer than the cranio-caudal spine. New virtual methods have allowed us to observe the changes in ROM of the vertebral column in a range of Crocodylomorph species, that could give us new information on their evolutionary history.
1 - Division of Paleontology, American Museum of Natural History, New York, USA 2 - Department of Earth Sciences, Univeristy of Cambridge, Cambridge, UK 3 - Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland 4 - Department of Earth and Planetary Sciences, University of California, Davis, Davis, USA
Ichthyosauridae is a monophyletic ichthyosaur group known from abundant fossil material almost exclusively from the Lower Jurassic of the United Kingdom. The most recent taxonomic review recognized two valid genera within the clade – Ichthyosaurus, comprising six species, and Protoichthyosaurus, including two species. Here, we present a new ichthyosaurid from the Lower Jurassic of Warwickshire, United Kingdom, represented by an almost complete, three-dimensionally preserved skull and mandible in occlusion. The new taxon is one of the largest ichthyosaurids reported to date and diagnosed by a unique combination of morphological character states, which include a moderate overbite, an anterior terrace of the supratemporal fenestra, a posteroventral process of the postorbital, and a posterior process of the jugal. An expanded, specimen-level phylogenetic analysis of Ichthyosauridae, based on a previously published dataset, places the new taxon within a group of specimens previously referred to Protoichthyosaurus, but outside a clade comprising the type specimens of Protoichthyosaurus. This has implications for the systematics of Ichthyosauridae and enables a critical revision of several cranial characters used in previous studies of ichthyosaurid taxonomy. Our results demonstrate the importance of specimen-based phylogenetics in vertebrate palaeontology and encourage additional work on the anatomy, taxonomy, and phylogeny of Ichthyosauridae.
1 - Hungarian Natural History Museum, Baross u. 13, Budapest 1088, Hungary 2 - ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology, Pázmány Péter sétány 1/C, Budapest 1117, Hungary 3 - Fossil Reptiles, Amphibians and Birds Section, Natural History Museum, Cromwell Road, London, SW7 5BD, United Kingdom 4 - Department of Propulsion Technology, Széchenyi István University, Egyetem tér 1, 9026 Győr, Hungary 5 - University of Szeged, Interdisciplinary Centre of Excellence, Department of Applied and Environmental Chemistry, Rerrich Béla tér 1., 6720, Szeged, Hungary 6 - Faculty of Geology and Geophysics, University of Bucharest, 1 Nicolae Bălcescu Avenue, 010041 Bucharest, Romania 7 - HUN-REN–MTM–ELTE Research Group for Paleontology, Pázmány Péter sétány 1/C, Budapest, H-1117 Hungary 8 - ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Physical Geography, Pázmány Péter sétány 1/C, Budapest 1117, Hungary
Ornithopod dinosaurs evolved numerous craniodental innovations related to herbivory, and precise occlusion was critical for efficient digestion. Nonetheless, little attention has been given to the relationship between occlusion, tooth wear rate, and tooth replacement rate within the group. We reconstructed tooth wear rates in five non-ornithopod genasaurians and 15 ornithopods by measuring tooth replacement rates and volumes of tooth wear, and document changes in dental microwear pattern. Our results show that total tooth volume per jaw quadrant and rates of tooth wear increased steadily during ornithopod evolution. Increased wear resulted in asymmetrical tooth crown formation in Late Jurassic ornithopods and in faster tooth replacement rates (>1 replacement tooth) in multiple lineages by the mid-Cretaceous. Microwear displays a contrasting pattern, with decreasing complexity, pit percentages and pit size in deeply-nested and later-occurring taxa. Ankylosaurs, conversely, retain primitive dental features, despite the fact that dental occlusion became widespread in the clade by the mid-Cretaceous. We hypothesize that while early ornithopods were browsers and/or frugivores, deeply nested iguanodontians became bulk feeders, eating tougher, less nutritious plants. This trend correlates with increasing body mass and longer gut passage times that likely contributed to their ability to thrive on low-quality forage.
1 - Hungarian Natural History Museum, Baross u. 13, Budapest 1088, Hungary 2 - ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology, Pázmány Péter sétány 1/C, Budapest 1117, Hungary 3 - Supervisory Authority for Regulatory Affairs, Geological Survey, Department of Collections, Stefánia út 14., Budapest, H-1143 Hungary 4 - HUN-REN–MTM–ELTE Research Group for Paleontology, 1083 Budapest, Ludovika tér 2., Hungary
In the Mecsek Mountains, southern Hungary, a roughly continuous Upper Triassic-Lower Jurassic continental to shallow marine sequence is exposed. Within this sequence, the lower part of the Mecsek Coal Formation contains the Triassic-Jurassic boundary, according to palynological studies. Apart from a few scattered finds and footprints of theropod dinosaurs (Komlosaurus carbonis), this formation yielded no significant continental vertebrate remains to date. Recently, we discovered a thin horizon among the lowermost, coal-bearing layers, from which hundreds of teeth and bone fragments were screen-washed. The finds represent amphibians, sphenodontians, lepidosauromorphs, possible archosauromorphs and cynodont synapsids. This latter group is represented by premolariform and sectorial teeth, attributable at genus level at least to Meurthodon, originally described from the Saint-Nicholas-de-Port site in eastern France. This further strengthens the Rhaetian age of our finds and thus this fauna pre-dates the Triassic-Jurassic extinction event.
As there is a similarity with the Rhaetian fossil record of eastern France, we hypothesize that the Mecsek Mountains being, in this time south-southeast from the Bohemian Massif, might have had land connection with more western parts of Europe.
1 - Natural History Museum 2 - University of Southampton
Understanding the relationship between environmental perturbations, physiological traits of organisms, and their evolutionary consequences is important because it allows us to predict the impact of anthropogenic climate change on current ecosystems, and to better quantify the role of climate change in deep time evolutionary trends.
Physiology provides the link between physical and biotic changes in the environment and their effects on an individual animal. Field metabolic rate (the energetic cost of living) integrates a wide range of potential physiological and behavioural responses to environmental change. Monitoring how individual field metabolic rate varies in response to environmental change within and across species can therefore provide a sensitive test of climate-organism interactions.
In my PhD, I am using a novel proxy based on the stable carbon isotope compositions of carbonate biominerals, to reconstruct field metabolic rates in modern and fossil marine animals. We aim to use our proxy to determine relative metabolic rates across taxa and to quantify how sensitive animal physiology is to temperature change.
1 - Natural History Museum, London, UK 2 - University College London
As global temperatures have increased with Anthropogenic climate change, some fish species have decreased in size. Smaller body sizes may negatively impact reproductive success and lead to population declines in slow reproducing, economically important families like Trachichthyidae (also known as ‘Slimeheads’). However, testing the temperature-size relationship in extant Trachichthyidae is challenging and research is limited. An extinct Trachichthyidae genus, Hoplopteryx, survived millions of years of climate instability through the Cenomanian to Campanian stages (100 - ~72 Ma) of the Late Cretaceous. This study used extensive collections of well-preserved fossils of this genus from the English Chalk, housed in UK institutions, to investigate Hoplopteryx body size changes through the Late Cretaceous. Size data were then compared to palaeotemperature estimates from oxygen isotope analysis of bulk chalk matrix attached to each specimen. Results showed a significant negative relationship between δ18O-derived palaeotemperature estimates and body size in the species Hoplopteryx lewesiensis, but a similar relationship at the genus level was not significant. These findings support the prediction that fish shrink in size in warmer seas and are the first evidence of this effect in Trachichthyidae. Further research should address the influences of ontogenetic and sexual variation on the observed temperature-size relationship.
1 - Department of Medicine, University of California Los Angeles, Los Angeles, United States 2 - Foundation for Scientific Advancement, Sierra Vista, Arizona, United States 3 - Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Tokyo, Japan 4 - School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China 5 - Lyme Regis Philpot Museum, Dorset, United Kingdom 6 - School of GeoSciences, The University of Edinburgh, Edinburgh, United Kingdom
The non-pterodactyloid pterosaurs are defined by their long stiffened tails terminating on an elaborate soft tissue vane. Their function is of contention, postulated on facilitating social signalling or acting as a tool of flight control. The soft-tissue "vane" has been observed in different non-pterodactyloid clades, including over a dozen specimens of Rhamphorhynchus. The sizeable vane would compromise the aerodynamic control and efficiency of the animal if it fluttered during flight. The vane has to maintain stiffness so as not to be detrimental to the aerodynamic performance of the animal. Helping to understand the internal morphology of the vane and its behaviour during the flight is Laser-Stimulated Fluorescence (LSF). The LSF scans performed on Rhamphorhynchus specimens (including the previously undescribed NMS G.1994.13.1) reveal a previously unseen structural feature: an elastic cross-linking tubular lattice within the tail vane. The lattice supported a tensioning system maintaining vane stiffness, facilitating function in flight control and social signalling.
1 - NHM 2 - UCL
Recent discoveries in the Middle and Late Triassic deposits of Africa highlight the importance of areas outside western Gondwana (South America) to our understanding of early avemetatarsalian evolution. For example, the archosaur fauna of the Tanzanian Manda Formation contains three key avemetatarsalian taxa; potentially the earliest dinosaur, Nyasasaurus; the aphanosaur, Teleocrater; and the silesaurid Asilisaurus. The description of another silesaurid, Lutungutali sitwensis, from the similarly-aged Ntawere Formation of neighbouring Zambia hints that an equally diverse assemblage may be present. Another notable aspect of these faunas is the presence of unusually large silesaurids: a partial femur from the Manda Formation suggests an individual of ~3 m in length and another from a potentially even larger individual has been reported from the Ntawere Formation. It is currently unclear whether these are new taxa or later ontogenetic stages of described taxa from these formations. Two Ntawere Formation specimens from the NHMUK collections are currently being described: one of these, NHMUK PV R37051, is a fragmentary femur from another large silesaurid. It is hoped that an osteological description and histological analysis of NHMUK PV R37051 will help shed some light on the taxonomic and size diversity of the Ntawere Formation silesaurids.
1 - Sezione di Paleontologia dei Vertebrati, Museo di Storia Naturale di Milano, Milan, Italy 2 - University of Portsmouth, School of the Environment, Geography and Geosciences, Portsmouth, UK 3 - Dipartimento di Scienze della Terra, Sapienza Università di Roma, Rome, Italy 4 - Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, MD 21205 5 - Associazione Paleontologica e Paleoartistica Italiana (APPI), Parma, Italy 6 - Department of Geology and Health and Environment Laboratory, Hassan II University of Casablanca, Casablanca, Morocco
Spinosaurus is one of the largest and most derived members of the Spinosauridae, a clade of theropod dinosaurs linked to freshwater environments from the Early and mid-Cretaceous of Eurasia, South America, and North Africa. With a unique suite of highly derived anatomical features, Spinosaurus has captured the attention and interest of researchers and the public ever since it was first discovered. It is characterised by an elongated skull with retracted nostrils, a specialised sensory system powered by hyperdeveloped branches of the trigeminal nerve, conical and well-spaced teeth, widespread osteosclerosis across the postcranial skeleton, elongated neural spines of the dorsal vertebrae that form a distinctive sail, proportionally short hind limbs, flattened pedal unguals and a long functional hallux, as well as a deep and narrow, paddle-shaped tail. Most of these adaptations have been interpreted as strong indicators of a semi-aquatic and piscivorous lifestyle in Spinosaurus, but the degree to which they facilitated different modes of locomotion in water and on land remains controversial. Ongoing discoveries and reviews of existing fossils continue to advance our understanding of the anatomy and palaeoecology of this enigmatic theropod. Here, we present a summary of recent findings regarding surface swimming and subaqueous hunting capabilities in Spinosaurus.
1 - Institute of Geography and Earth Sciences, Department of Palaeontology, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest 1117, Hungary 2 - Department of Geology and Paleontology, Hungarian Natural History Museum, Ludovika tér 2, H-1083 Budapest, Hungary 3 - University of Bucharest, Department of Geology, Mineralogy and Palaeontology, 1 N. Bălcescu Blvd., 010041 Bucharest, Romania, 4 - HUN-REN-MTM-ELTE Research Group for Paleontology; Ludovika tér 2, H-1083 Budapest, Hungary
Hadrosauroid bones occur relatively frequently in the Maastrichtian of Transsylvania, but are mainly isolated, fragmented, and lack diagnostic features, hindering their proper taxonomic identification. Therefore, these were usually referred previously to Telmatosaurus transsylvanicus, the only nominally described Transylvanian hadrosauroid. Recently, a small-sized partial skeleton of a hadrosauroid with associated skull and postcranial elements was discovered near Vălioara in the new Fântânele3 site from the Densuș-Ciula Formation. This partial skeleton shows several differences from Telmatosaurus, especially in the morphology of the nasal and the coronoid process, the proportions of the dentary, and the morphology and foramina pattern of the surangular.
Thorough comparisons prompted by our discovery revealed that previously collected hadrosauroid fossils from the Hațeg Basin are also in need of revision, while prompting a new, revised diagnosis of T. transsylvanicus as well.
The new hadrosauroid material from Fântânele3 can help in clarifying the taxonomic status, and updating the diagnosis, of Telmasosaurus, while also appears to support earlier hypotheses that more than one hadrosauroid taxon was present in the Hațeg Island fauna during the Late Cretaceous. Furthermore, it also contributes to the better understanding of the phylogenetic affinities, the palaeobiogeographical distribution and evolution of the different European insular basal hadrosauroids.
1 - School of Earth Sciences, University of Bristol, Bristol BS8 1TF, U.K. 2 - 131 New Road, Woodston, Peterborough, Cambridgeshire PE2 9HE, U.K. 3 - Fossil Reptiles, Amphibians and Birds Section, The Natural History Museum, Cromwell Road, London SW7 5BD, U.K. 4 - School of Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus,European Way, Southampton SO14 3ZH, U.K. 5 - Bristol Museum & Art Gallery, Queens Road, Bristol BS8 1RL, U.K.
Pachystropheus rhaeticus is an enigmatic marine diapsid reptile found in British Upper Triassic (Rhaetian) deposits. It was identified as the oldest choristodere based on similarities between postcranial-bones and a sole cranial-element. We re-study all available Pachystropheus material, identifying all skeletal elements that are plausibly referrable to the genus. We reject some identifications, in particular the sole crainial element described, showing that supposed skull elements instead belong to coelacanths. We present CT data for the first time and new palynological data from Pachystropheus-bearing strata, providing a clearer picture of its stratigraphic distribution and the paleoecology of the Penarth Group. The reassessment of its phylogeny using new character informative data, places Pachystropheus as the thalattosaur, a lineage of marine reptiles abundant throughout the Triassic. We demonstrate that a specimen of Pachystropheus previously reported from the Lower Jurassic is likely from the Late Rhaetian, meaning the taxon does not extend across the end-Triassic Extinction. This extends the known geological range of thalattosaurs from the Norian–Rhaetian boundary to the latest Rhaetian. Similarities in the postcranial skeleton between Pachystropheus and other askeptosauroid thalattosaurs, suggest it was able to move on land, but was most likely a primarily marine predator with a distinct ecological niche.
1 - Lyme Regis Philpot Museum
Ichthyosaurs, often referred to as ‘fish lizards’, are an extinct group of marine reptiles that occupied the oceanic regions throughout the Mesozoic era. Since the earliest years of their discovery, an increasing interest in the study of these prehistoric vertebrates has resulted in a range of implications concerning their lifestyle and biology. Significant advancements within the field of fossil preparation means we now can observe the fossil remains of these creatures in far greater detail than ever before, thus resulting in previously overlooked elements to be recognised. Thanks to these advancements, we now know much more about the diet of ichthyosaurs, with many specimens exhibiting phosphatic masses underlaying the ribs, in which cephalopod hooklets can be observed. We report here an Ichthyosaurus communis specimen exhibiting an exceptional degree of soft-tissue preservation, recovered from Black Ven (Charmouth Mudstone Formation, Lower Lias Subgroup) of Lyme Regis in 2004 by Derrick Powell. A phosphatized mass located in the posterior region of the stomach is here interpreted to be the first recorded instance of 3D intestinal preservation in an Early Jurassic Ichthyosaur, further supplementing our understanding of these animals’ biology and degrees of gut preservation that can occur.
Bayesian and Implied Weights parsimony approaches support tyrannosaurid anagenesis and reveal potentially novel Daspletosaurus metaspecies
1 - University College London
Tyrannosaurines were the dominant predators of Laramidian ecosystems during the Late Cretaceous. An anagenetic hypothesis for the evolution of derived tyrannosaurines in Laramidia has received much attention in recent years, although several studies disagree on the degree of anagenetic and cladogenetic evolution driving tyrannosaurine evolution. These studies have relied on phylogenetic results of equal weights parsimony analysis and do not consider the impact of alternative phylogenetic methodologies. Here, I build on previous work by applying maximum likelihood Bayesian inference and Extended Implied Weights parsimony analyses to competing datasets and show that both of these methods provide additional support for anagenetic evolution in tyrannosaurines. In species-level and specimen-level analyses, species of the Campanian taxon Daspletosaurus form a paraphyletic grade of tyrannosaurines leading to Tyrannosaurini. A fully-resolved specimen-level topology allows for the application of species delimitation techniques and reveals potentially novel metaspecies of Daspletosaurus, diagnosable by unique combinations of ancestral and derived characters. Future detailed description of the specimens analysed by this contribution and previous work may provide additional support for establishing novel Daspletosaurus metaspecies. This study reinforces the application of specimen-level analyses and the analytical benefits that come from accounting for homoplasy in such analyses by differentially weighting homoplastic characters.
1 - ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology, Pázmány Péter sétány 1/C, Budapest 1117, Hungary 2 - Hungarian Natural History Museum, Baross u. 13, Budapest 1088, Hungary 3 - Mécanismes adaptatifs et évolution (MECADEV), UMR 7179, MNHN, Paris, France 4 - Institut de Systématique, Evolution, Biodiversité (ISYEB), MNHN, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France
Aquatic birds exhibit a wide range of ecologies and locomotion types. While species with the best aquatic skills have lost their ability to fly or move effectively on land, others excel in water, on land, and in the air, despite the different physical characteristics associated with each medium. This project aimed to analyse the shape variation of limb long bones of different aquatic birds using 3D geometric morphometrics, as well as to explore the inner structure of their bones using both qualitative and quantitative approaches, in order to understand the relationship of these characteristics with locomotor abilities. In terms of shape, although variation is mainly driven by phylogeny, different morphologies linked to given types of locomotion can be distinguished and characterized. Moreover, the shape of the ulna is influenced by both size and aquatic propulsive techniques even when phylogeny is taken into consideration. As for the inner structure, compactness and cortical thickness generally increase in taxa best adapted to diving, particularly in flightless species, especially penguins. However, the compactness of different bones can vary within a skeleton. These results could help us to better understand aquatic birds’ evolution and can be of great use in inferring extinct species' ecologies.
1 - Eötvös Loránd University Department of Paleontology 2 - University of Tübingen Institute of Geosciences
Doratodon is an enigmatic ziphodont mesoeucrocodylian known from the Santonian of Hungary, the Campanian of Austria and Spain, and the Maastrichtian of Romania. While its taxonomic position has been a subject of debate since the end of the 19th century, due to the fragmentary nature of its remains, new material from the Santonian Iharkút locality calls its previously assumed ziphosuchian affinity into question. A nearly complete cranium uncovered in 2018 referred to Doratodon shows many anatomical characteristics typical of the neosuchian clades Paralligatoridae and Atoposauridae. Phylogenetic analyses on both the type locality and the Iharkút Doratodon material imply a phylogenetic connection to these clades, with its similarities to Ziphosuchia being a result of ecomorphological convergence. As Doratodon was one of the faunal elements in the Iharkút locality previously assumed to be of Gondwanan origin, this new discovery weakens the presumed faunal link between Africa and Europe, and suggests that the Late Cretaceous European crocodyliform record is dominated by Laurasian groups.
1 - Facultad de Ciencias, Montevideo, Uruguay 2 - 2Escuela Tecnológica Superior de Administración y Servicios 3 - Museo Nacional de Historia Natural (MNHN)
The living Patagonian mara Dolichotis patagonum is the second largest caviid after capybara Hydrochoerus hydrochaeris, hare-like in appearance, cursorial herbivore rodent feeding mostly on fruits and grasses. In the present occurs in Argentina (28°S-50°S) in lowland habitats, semi-arid thorn-scrub, open grasslands and shrub-land steppe. In this contribution is studied a skull partially preserved (FCDP-V-2785), referred to D. patagonum, unearthed from late Pleistocene beds (Sopas Formation) of northern Uruguay (Arapey Grande River, Salto Department). Body mass estimate, bivariate and Principal Component analysis-PCA were performed including current specimens of D. patagonum, the Chaco mara Dolichotis salinicola and extinct dolichotine species. The body mass estimate using regression method and geometric similarity suggests a 6-9 kg range for the studied specimen, consistent with D. patagonum (7-8 kg), notably larger than D. salinicola (1-2.3 kg). In the quantitative comparisons it is included, together with the extinct D. platycephala, in the variation of D. patagonum differing in part from D. chapalmalense and more clearly from D. salinicola and the extinct D. minor and Prodolichotis prisca. It is discussed the implication of the different geographic distribution of the living Patagonian mara in late Pleistocene of South America and its paleoenvironmental significance. Contribution to CSIC-I+D-Grupos “Paleontología de Vertebrados”.
1 - Facultad de Ciencias, Montevideo, Uruguay 2 - Museo Nacional de Historia Natural (MNHN) 3 - Museo Nacional de Historia Natural (MNHN), Montevideo, Uruguay
The New World vultures form a widespread group of soaring scavengers in the Americas. This clade currently comprises seven species in five genera, divided into two groups: the condors (Gymnogyps, Vulture) and the smaller vultures (Coragyps, Cathartes, Sarcoramphus). The Pleistocene record of these birds is diverse and widely distributed. In the present contribution, we describe a fossil from the late Pleistocene-early Holocene sediments of Canelón Chico locality (Canelones Department, southern Uruguay). The material (MNHN-3948) consists of a distal fragment of a right tarsometatarsus. The linear size of the fossil is within the range of the largest male Vultur specimens. However, the cross-section of the shaft, the position of the distal foramen and the orientation and depth of metatarsal facet distinguish it from living Vultur. The notorious flattened shaft may indicate locomotory adaptations not observed in the large condors but characteristic of the smaller Cathartes species. This material suggests a new form of Cathartidae from the Quaternary of South America, and extensive studies are ongoing for a more concrete taxonomic determination. It also provides new insights into the trophic roles of scavenger birds during the Late Pleistocene of South America. Contribution to CSIC-I+D Grupos “Paleontología de Vertebrados” C302-347.
1 - Swansea University 2 - University of Zurich 3 - University of Fribourg
Diversity is unevenly distributed across the tree of life. What traits determine a clade’s capacity to persist and diversify? Indeed, for over 400 million years, sharks have exhibited remarkable adaptability and resilience, allowing them to survive multiple environmental changes and extinction events. Nevertheless, present-day pressures such as overfishing pose significant threats to the survival of modern species, leading to one third of their diversity threatened with extinction.
By creating the first phylogeny of all living and extinct shark species, we aim to investigate whether age (time from origination) determines its shark’s speciation potential. Furthermore, using a novel and comprehensive trait dataset, we will assess whether shark’s evolutionary and ecological distinctiveness in the past determines its future performance. To do this we will use photo-recognition and machine-learning to infer the traits of extinct elasmobranch species.
Utilising these cutting-edge methods that integrate paleontological and genomic data with advanced analytical techniques will provide critical insights that can help inform conservation and management efforts in the future.
1 - University of Portsmouth
The first published reconstruction of a dinosaur was the lizard-like Megalosaurus in Georg August Golduss’ classic 1831 illustration Jura Formation. Ever since, life restorations of Megalosaurus bucklandii have been important components of British palaeontological culture. Reconstructions of this iconic species are contentious, however, with M. bucklandii variably regarded as unrestorable, a ‘generic’ large theropod, or something more distinct. A historically confused and unassociated type series and the poor megalosaurine fossil record are the main causes of these varied opinions. As part of celebrations surrounding the 200th anniversary of the naming of M. bucklandii, modern megalosaurine discoveries and current understandings of early theropod phylogeny were used to reassess the likely appearance of the first-named dinosaur. Megalosaurus were probably long-jawed and blunt-snouted, with nasal crests and minimised, scale-covered supraorbital ornaments. Their arms were probably of moderate length and generously muscled, but with short antebrachia. Their hindlimbs were likely stout and married to a shallow pelvis. Estimating their body lengths is challenging, but body fossils indicate values approaching 8 m. Footprints referred to M. bucklandii indicate larger individuals, however, perhaps closer to 10 m. Efforts at restoring Megalosaurus remain tentative, but they neither seem unrestorable nor ‘generic’ in their anatomy.
1 - University of Reading 2 - University of Lincoln
Archosauriformes are a diverse clade encompassing both extinct (archosaurs, dinosaurs & pterosaurs) and extant species (crocodiles & birds). They are identified on the basis of a distinctive craniofacial feature in their snout known as the antorbital fenestra (AOF). Despite its prevalence in both extinct and extant archosaurs, its function and importance have been equivocal, as its soft tissue content have been debated for almost a century with suggestions such as AOF housed a gland, or a muscle or an air sac. There are multiple hypotheses for the function of this structure. Some believe that it contained an air sac, while others believe that it was just a cavity that was opened up by archosaurs to lighten the skull. Its morphology and function are yet to be properly tested biomechanically. Here we present a comprehensive dataset of almost 100 species of Archosauria throughout the Triassic period which tracks the origin of AOF and its morphological changes in size. As previous studies have shown most significant changes in relative skull size in Archosauria occur soon after the origin of most terrestrial archosauriformes and their skull sizes become disproportionally smaller with increasing body sizes. Our analyses show and support that although the skull sizes become disproportionally smaller with increasing body size, AOF scales isometrically with skull size as compared to body size and diet. This trend is largely independent of temporal distribution, species richness and phylogeny. Our findings lay the groundwork for a broader, deep-time comparative analysis into AOF’s size and shape evolution across all of Archosauria, and it will also help us gain insight into the mechanical trade-offs that influence the size changes in AOF relative to skull size.
1 - University of Bristol
Palaeontology shows us that many billions of species that once existed are now extinct, and their natural extinctions enabled new species to inherit the Earth. We identify mass extinctions during which 50–95% of species were killed off, and yet life always recovered. In fact, some of the great diversifications in the history of life were triggered by the opportunities afforded by mass extinctions. So, extinction in the context of modern life, especially the needless slaughter of species by human action or carelessness, is inexcusable. Who does not mourn the loss of the Polynesian tree snail or the dodo? Palaeontologists of course work on longer time scales and can see how extinction events have released the potential of new groups to show their evolutionary mettle. This is one of the wonders of exploring the geological record but should not allow us to think we can hasten the extinction of any modern species.
1 - University of Southampton
The placenta is a temporary organ which mediates nutrient exchange between the fetus and the mother. In mammals, all placentas are descended from a single common ancestor and their functions are conserved across species. However, the placenta exhibits remarkable structural diversity, the selective pressures of which are poorly understood. These may include major biological phenomena, such as the evolution of different life history strategies or offspring-parent conflict. We will be unable to understand the role of these drivers in placental evolution until placental structure can be accurately quantified and the link between function and structure understood. Historically, placental structures have been grouped into qualitative categories. Assessing the placenta, or any biological structure, on this basis could be problematic if it hides biological variation or fails to resolve the structure as an integrated multiscale system. To address this, we are developing correlative multiscale 3D imaging workflows to image the mammalian placenta from the whole organ to the nanoscale and using the results to computationally model physiological function within realistic tissue architectures. Using examples from species from mice to giraffes, I will show how our approach is being used to unravel the drivers of placental evolution.
1 - Tetrapod Zoology
to be added
1 - Università Campus Bio-Medico di Roma
The study of genital bones in mammals offers unique insights into evolutionary biology, revealing patterns of adaptation and diversification. The evolutionary trajectories and biological roles of genital bones will be explored, with a focus on the baculum (os penis) in males and the baubellum (os clitoridis) in females. These structures, while present in many mammalian lineages, exhibit remarkable variability in presence, size, shape, and function across different species. Factors such as mating systems, reproductive strategies, and ecological niches play crucial roles in the retention or loss of these bones. By integrating fossil evidence and anatomical studies, the aim is to shed light on the complex interplay between structure and function in the evolution of genital bones, tracing the morphological changes that led to the highly specialized forms observed today. The presence of these bones in both males and females across various species suggests a complex interplay of evolutionary forces. Understanding the evolutionary patterns and biological significance of genital bones provides deeper insights into mammalian reproductive evolution, highlighting the intricate relationship between form, function, and evolutionary fitness. A comprehensive overview of current research findings will be provided, stimulating further discussion on this intriguing aspect of mammalian evolution.