We also rectify some previous interpretations. There are no identifiable quadratojugals, and the identification of cervical ribs is not supported. The presacral region is composed of 15 vertebrae with a unique atlas-axis complex, instead of 14 vertebrae with a bipartite atlas. The configuration of the pelvic girdle is not very clear, although it is likely more plesiomorphic than the anuran-like condition previously assumed.
reconstruction and the minimum convex hull method
elements, notably the extant Giraffa camelopardalis. The extinct, ‘giant’ genus Sivatherium
is an unusual giraffid, as it possessed relatively short stout limbs, a short neck, and ornate
ossicones. Sivatherium spp. are anecdotally the heaviest of the giraffids, having been
historically compared to the size of African elephants. We set out to estimate the body mass
of a representative adult of the type species Sivatherium giganteum, using the minimum
convex hull method. The reconstructed composite skeleton was based on fossil material
(including the type specimen) from the Natural History Museum, London. Missing elements
were replaced with those from a previously digitised Giraffa camelopardalis skeleton, or
estimated from interspecific scaling equations. The giraffe elements were scaled to known
Sivatherium skeletal dimensions. The validity of the resulting model was then tested against a
different interspecific scaling equation for other artiodactyls. Using a previously published
volumetric scaling method, the convex hull volume yields an estimated minimum body mass
of 1786 kg (1500 - 2000 kg). Due to the uncertainty surrounding the missing skeletal
segments, a sensitivity analysis was performed, where the linear dimensions of the scaled
Giraffa elements were increased and decreased by a factor of 10%. This resulted in modest
changes to the estimated body mass. The volumetric mass estimates were then compared with
those calculated from ‘single bone’ bivariate interspecific scaling equations. The resulting
discrepancies (for example humeral circumference) highlight parts of the skeletal anatomy of
Sivatherium which may be morphologically and functionally unusual.
Consequently, studying the evolution of brains in bird lineages should provide an insight into how their ability to fly evolved. Understanding how brain shape and behaviour are linked in extant species provides a good approximation of that correlation in fossils; however, brains are not preserved in extinct birds. The solution is to reconstruct the endocasts of fossils, and use that data to study how bird brains changed over time.
We studied a sample of 70 bird species with a great diversity of behaviours, and then applied geometric morphometric methods on the endocasts of those animals in order to see the link between behavior and endocast shape.
Our results show some relationship between behaviour and brain shape, with discrimination mostly by ecology instead of phylogeny. What was particularly apparent was the relation between brain shape and dietary/locomotive behaviours. In some groups there is still also a tiny phylogenetic signal, which could be explained by the fact that the divergence between families happened too suddenly for any ecological factors to affect their evolution.
Keywords: Bird, brain, endocast, shape, behaviour, morphometry
Acknowledgements: The authors want to acknowledge the GACR grant No. P302/12/1207
clearly full of misunderstandings and paradoxes.
Until most recently it was always claimed, that in ‘Archaeopteryx’, including also
later finds, the feathers were only preserved as imprints (implying no material left apart from
the black of the single feather). Early this century when scrutinizing the London specimen a
second time, I discovered that in the counterpart some tiny patches of some yellowish
material from the flight feathers was preserved included in whitish secondary calcite (really
not surprising, as most ‘Archaeopteryx’ preserve the keratinous claws of the toes). I
suggested analysing a few mm of these remains of feathers for a joint publication, but the
‘authority’ said “No – nothing to be removed !” (recall the entire skull had long ago been
taken completely out – and is now scanned). I also found a small (never reported) feather at
the thumb that might be an alula, also preserved with material intact, but that has been denied
publication in high profile journals by reviewers stating “I don’t believe it” and similar
unsubstantial remarks (e.g. misunderstanding simple cladistic arguments). In 2010 Bergmann
et al. published their analysis of the same kind of ‘feather material’ from the 10th specimen.
Almost certainly most specimens (not Berlin) must have had such preservation, and probably
most material fell out when the limestone was split (may even have been brushed away!).
This is a cautionary tale: prejudicial and censorious attitude by ‘authorities’ and referees
prevented scientific advance.
deep gnathostome phylogeny
These hypotheses were tested in a dataset of leg bone lengths and diameters for 38 species of flightless birds including 23 extinct taxa. Nineteen volant relatives were measured to provide ancestral models. Measurements were size-corrected and input into a factor analysis. Differences (Δ) in scores between flightless species and ancestral models were input into multiple regressions. Independent variables for regressions were: Δ femoral circumference, estimated time since the loss of flight, and whether the species was present on an island or continent. One-sample Wilcoxon Signed Rank tests were carried out on Δ factor scores and femoral circumferences to test for directionality in the evolution of limb bone proportions and body size.
No evidence for directionality was found in these analyses with few relationships between the changes in proportions and predictor variables. One pattern found was that ratites outside of New Zealand have longer, narrower distal limb bones than those species found in New Zealand. The trajectories of change in leg bone proportions are far more complex than those seen in the wings and likely reflect variation in ecology rather than any universal selection pressure.
We quantified disparity for >350 neopterygian species across 150 million years of the Mesozoic. The analyses reveal that holosteans were far more diverse in the past, showing greater disparity than teleosts across the Triassic and Early Jurassic. Sustained teleost diversification from the Early Jurassic onwards led them to approach holostean levels of disparity in the Middle Jurassic, before achieving greater disparity than holosteans from the Late Jurassic onwards, over 100 million years after the unequivocal origin of neopterygians in the fossil record. Surprisingly, although the Late Jurassic teleost takeover coincides with the arrival of crown group teleosts – taxa previously shown to display exceptional phenotypic rates and innovation – they are not responsible for the Late Jurassic rise in teleost disparity. Instead, it is the presence of desperate, early diverging teleost clades, such as Pachycormids, Aspidorhynchids and Pycnodonts, that drive the initial teleost takeover. Nevertheless, as the Cretaceous wore on, crown teleosts became an increasingly important contributor to overall teleost disparity.
mammals in recent years. These finds reveal hitherto-unsuspected ecomorphological diversity
that suggest mammals experienced a major adaptive radiation during the Middle to Late
Jurassic. Patterns of mammalian macroevolution must be reinterpreted in light of these new
discoveries, but only taxonomic diversity and limited aspects of morphological disparity have
been quantified. We assess rates of morphological evolution and temporal patterns of
disparity using large datasets of discrete characters. Rates of morphological evolution were
significantly elevated prior to the Late Jurassic, with a pronounced peak occurring during the
Early–Middle Jurassic. This intense burst of phenotypic innovation coincided with a stepwise
increase in apparent long-term standing diversity, and with the attainment of maximum
disparity, supporting a “short-fuse” model of early mammalian diversification. Rates then
declined sharply, and remained significantly low until the end of the Mesozoic, even among
therians. This supports the “long fuse” model of diversification in Mesozoic therians. Our
findings demonstrate that sustained morphological innovation in Triassic stem-group
mammals culminated in a global adaptive radiation of crown-group members during the
Early–Middle Jurassic.
common question that has arisen during my work is whether the weight of a dinosaur can be
estimated from its tracks. Indeed, in recent years a small number of studies have attempted to
do just that based on the depths of fossil footprints. Such studies require reconstructing the
mechanical properties of the substrate, and then using force-displacement relationships to
determine the range of possible loads. However, the interaction between the foot and the
substrate is highly complex, and treating the track-forming process as a simple vertical
indentation accomplished with a single load is likely to be extremely inadequate. The track
forming process is dynamic, and the load applied, expressed as underfoot pressure, changes
throughout the step cycle, meaning there is no ‘one’ load to reconstruct. There is also rarely a
single depth with which to measure vertical displacement. Compounding matters further, if
there is a flat base to a track, the likelihood based on experimental data is that the foot was
supported by a firmer substrate beneath. This means that even if conditions are accurately
assumed for the surface track-bearing sediment, ultimately that layer has not resisted the
weight of the animal, and it is a deeper, mechanically different substrate that has supported
the animal’s weight. Based on the data and inferences gained through experimentation and
theory, it is unlikely that footprints can be used as an adequate means of estimating mass in
extinct taxa.
anatomy
locomotion. The aerodynamic function of the tail is facilitated by its derived structure,
composed of an articulated fan of feathers (rectrices), unique soft tissues, and, critically, a
specialized caudal skeleton. Recent paleontological and neontological comparative research
support the hypothesis that these elements have evolved in a coordinated manner throughout
early avialan and modern neornithine history. Here, we explore several lines of evidence to
understand how interactions among the elements of the tail apparatus have shaped the
evolution of skeletal variation in this system. We test two predictions: (A) that the evolution
of costly, sexually dimorphic tail feathers necessitates concomitant phenotypic changes in the
underlying caudal skeleton that supports the tail fan and (B) that the free caudal vertebrae and
the terminal pygostyle exhibit phenotypic integration and can be predicted to evolve in a
coordinated manner. Caudal skeletal morphology was quantified in several passeriform taxa
and permutational MANOVA was used to test whether males and females of dimorphic
species exhibit sex differences in key caudal traits. Skeletal dimorphism was not consistently
detected; suggesting caudal skeletal morphology in these taxa is likely influenced more by
phylogeny and locomotor function than by its relationship with tail fan shape. Using a
phylogentic implementation of integration analysis, we recover evidence of significant
integration between the pygostyle and other caudal skeletal elements. This supports the
hypothesis that the tail skeleton evolves as a whole despite its structural and functional
regionalization. Together, these findings shed new light on the processes that have shaped
morphological variation in this system and can guide future work at the interface of avian
origins, comparative anatomy, and developmental biology.
This study uses landmark geometric morphometrics to analyse the shape of a phylogenetically and functionally diverse sample of avian pelves. The pelvis and synsacrum is the most complex structure in the skeleton of the hind-limb of birds and searching for correlations between shape and function require shape-based, multivariate analyses.
Landmarks were collected from complete pelves of adult birds for which the sex of the individual was known and a hind-limb functional group was assigned. These landmarks attempted to capture the shape of regions of the pelvis available for muscular attachment. Subsequently, the shape configurations were aligned and a principal components analysis (PCA) performed.
The results of the PCA show a significant difference and excellent separation between the shapes of pelvis found in different functional groups, demonstrating that shape of the pelvis is correlated to function of the hind-limb. This finding suggests many fruitful avenues of research are possible, including the prediction of life habit from pelvic shape and biomechanical analysis tailored to each functional group.
The investigation on the anatomy and variability of S. urbinai is based on several more or less complete skeletons and several hundreds of disarticulated bones, including skulls and postcranials. The fossils come from five different Peruvian localities (El Jahuay, Aguada de Lomas, Montemar, Sud-Sacaco, Sacaco) covering the age period from the Late Miocene to Early Pliocene, from about 9 Ma up to ca. 3.5 Ma. The overall cranial and postcranial anatomy of S. urbinai correspond in general well to that of extant penguins of the genus Spheniscus. However, it distinguishes from all extant Spheniscus species by a much more robust and longer beak terminating in a hooked tip, which resembles in size and shape more that of an albatross than that of any extant penguin. It thus might reflect a slightly deviant or more diverse diet.
The most common post-cranial elements have scrutinized through multiple linear measurements and their diversity are currently being reviewed through multivariate methods as part of this study. Preliminary evidence now demonstrates a quantified explanation of species diversity and patterns of allopatric/sympatric divergence.
Survival of elephant birds into the late Holocene has been documented by a small number of radiometric carbon dates with the latest presence date indicated at circa 1000AD and an unverified second-hand visual account from Etienne Flacourt (French governor of Madagascar in the 1600’s). Several questions remain over their extirpation and extinction, timing and drivers.
Humanity is often cited as the extinction driver of these giant ratites due to dated specimens falling after human colonisation of Madagascar. There remains no documented, verifiable evidence relating to human impact. Following the review of European collections, several specimens with potential evidence of direct human impact have been identified for closer investigation. The validity and implications of these specimens will be discussed.
The Downton Bone Bed contains not only vertebrates, but also a wide range of other fossils including bivalves, gastropods, ostracodes, arthropods, brachiopods and plants. This gives a snapshot into the Ludlow area during the late Silurian, a time of tremendous change, as the Downton Bone Bed was deposited on a near shore sand bar during the Lau Event, which is associated with the largest carbon isotope excursion in the Phanerozoic. Results suggest that the “Downton Sea” was a restricted environment indicated by the low diversity assemblages. The most common vertebrate in the Downton Bone Bed is the thelodont Paralogania ludlowiensis which makes up 81% of the total identified vertebrate fauna.
(Campanian-Maastrichtian) in Alberta, Canada
all southern Alberta rivers, a new dinosaur tracksite was discovered. Investigation of the site
in the spring of 2015 resulted in the discovery of another, even better set of tracks and
trackways, and while working on these first two more sets of tracks were found. Dinosaur
tracks and trackways are very rare in the Late Cretaceous of Alberta, so to find multiple sets
of trackways made by several different families of dinosaurs is newsworthy. The tracks were
made by small ornithopods, large ornithopods, ornithomimids - both adults and juveniles,
tyrannosaurs, and possibly birds as well. The tracks are hosted on single, large bedding
planes on the surfaces of large boulders that fell from high, steep cliffs. There are two
possible, mutually compatible explanations for the rarity of dinosaur tracks in this part of the
world - 1) the flat, well-watered coastal plain environment, with its shifting, meandering
rivers was not good for the preservation of tracks, and 2) the degree of lithification of most of
the sediments was too low to allow tracks to resist the rapid erosion they experience with the
modern climate.
beach at Lavernock, near Cardiff. Recently fallen blocks from a cliff were found to contain
the partial skeleton of a new juvenile theropod dinosaur. Comparison of lithology and bed
thickness enabled fairly precise placing of the new dinosaur within the in situ Blue Lias
(Jurassic, Hettangian) adjacent to the find. Strata exposed at Lavernock range from the
Mercia Mudstone Group (Triassic, Norian) to the lower portion of the Porthkerry Formation
(Jurassic, Blue Lias, angulata zone). The dinosaur-bearing horizon occurs above the last
Triassic conodont, but below the first appearance of Psiloceras planorbis, traditionally
regarded as marking the base of the Jurassic. We have correlated the Lavernock section with
the Austrian GSSP for the Jurassic System on the basis of known carbon isotope excursions,
which place the dinosaur-bearing horizon around 1.5m above the T/J boundary. Rhaetic
dinosaur remains are very rare in south Wales, and none have previously been found within
the marine Jurassic strata.
A second cliff fall in summer 2015 at the same site yielded two more blocks of bone with
remains of the same dinosaur to University of Portsmouth Palaeontology student Samuel
Davies who was undertaking his 2nd level project at the site. Some remains are still missing,
but the material collected so far makes this specimen the most complete theropod dinosaur
ever discovered in the Lower Jurassic of Europe.
We investigate Thylacoleo’s probable predatory mode of by statistical analyses of elbow-joint anatomy, comparing this enigmatic extinct marsupial with a large number of extant marsupials and placentals. Thylacoleo’s elbow morphology is unique, combining the capacity for stability in terrestrial locomotion with maneuverability of the forearm otherwise seen in arboreal mammals. We suggest that this elbow joint morphology, in combination with the large claw on the thumb and the blunt “caniniform” incisors, reflects a unique predatory mode: rather than using the claws to hold the prey and the canines for killing, as in extant large felids, we propose that Thylacoleo used its enlarged incisors to subdue the prey and a rapid movement of the forearm around the elbow joint (supination) to kill with its huge claw.
Since prehistoric times ancient Egyptians considered some animals to be sacred as symbols and expressions of divinity; the fossil bones at Qau maybe a function of this practice. This area of Egypt was a recognised cult centre of the god Seth who was frequently depicted as a hippopotamus. It is possible that the fossils were a form of local offerings to Seth perhaps functioning in a similar fashion to the use of animal mummies.
The excavators Guy Brunton and Flinders Petrie noted the importance of the fossil finds but never published a full account of their interpretation or documentation of species present. With time, records of their storage location became lost and no further research was published. The fossils are currently held at the Natural History Museum and are now the subject of a study to bring a paleontological understanding of these intriguing fossils and a re-evaluation their original archaeological context.
Tugulu Group (Lower Cretaceous) discovered in the Hami area, Xinjiang Uyghur
Autonomous Region of China. Among the hundreds of specimens of the sexually dimorphic
pteranodontoid Hamipterus tianshanensis are five three-dimensionally preserved eggs. They
are slightly asymmetric, with the length varying from 59-65mm and the average width around
34mm. The external surface is formed by a thin (~60μm) layer of calcium carbonate that
produces the cracking and crazing of the otherwise smooth external eggshell surface. Below,
there is a thin shell membrane (~11μm), that might have been originally thicker. All eggs
show depressions, clearly indicating their overall pliable nature. SEM analysis shows that the
eggshell structure is similar to some squamates.
Another important material comes from the Late Jurassic Tiaojishan Formation
(Liaoning Province). The counter slab (IVPP V18403) of a previously known wukongopterid
specimen shows the presence of two eggs, one preserved inside the body of the animal. SEM
analysis of the eggshell did not reveal an external calcareous layer suggesting that it was
either removed due to taphonomy or not present at all. Histological section of the femur lacks
medullary layer, a bone tissue reported in avian dinosaurs during ovulation and egg-laying
phase. Those specimens, associated with experimental taphonomic studies, show that
pterosaurs had two functional oviducts and laid eggs even smaller than previously thought,
indicating that they have developed a reproductive strategy more similar to basal reptiles than
to birds.
Mary Anning’s marine reptiles: taxonomy, systematics, morphometrics and evolution of the iconic Ichthyosaurus
Ichthyosaurus is the most famous of all fossil marine reptiles, yet its taxonomy and composition is little studied. Hundreds of Ichthyosaurus specimens are known, and at least five species are recognized by recent authors. The autapomorphies and diagnosis of both Ichthyosaurus as a whole and its constituent species are little studied and several specimens reveal a range of intermediate conditions between currently recognized species. We report the most comprehensive analysis of Ichthyosaurus ever undertaken, based on a large sample of specimens (>200) from across the Lias. Precise data on the stratigraphic position of specimens is scant; one aim of this study is to use palynomorphs to establish age and provenance. This work has resulted in: (1) Anatomical clarification of the status of Ichthyosaurus; (2) Understanding of the likely species composition within Ichthyosaurus; (3) Large-scale morphometric, systematic and phylogenetic analyses within the clade, and; (4) A clear understanding of evolutionary trends within Ichthyosaurus across the Liassic. Conclusions indicate that the validity of Ichthyosaurus is supported by autapomorphies. However, specimen clusters recovered by principal-component (PC) and size-constrained PC morphometric analyses do not correspond to currently recognized species. Ichthyosaurus spans a range of body sizes and individuals cluster into several size classes. Some represent ontogenetic stages within species. Other clusters exhibit trends in body size evolution throughout the Lias. This work helps clarify both the true diversity and evolutionary history of this iconic Liassic animal, first brought to scientific attention by Mary Anning over a century ago.
Pelomedusoides) from the Early Cretaceous Crato Formation, Brazil
formations, with very similar vertebrate faunas. Six valid turtle species are recognized for the
latter unit, of which only one, Araripemys barretoi, is also present in Crato Fm. A second
species, “Araripemys arturi”, was described, based on a very incomplete specimen from
Crato Fm.
Subsequently, A. barretoi and “A. arturi” were synonymised. The latter’s diagnostic
features were invalidated, those being: 1) ovoid-shaped carapace, whereas A. barretoi
displays a posterolateral angulation at the carapace lateral margin; 2) peripherals IX and X
equally long as wide; and 3) lack of arrow-shaped pedal unguals, present in A. barretoi. The
first has been proposed to be taphonomical or dubious due to the material incompleteness;
while the second could represent ontogenetic, sexual or individual variation; and the third, in
turn, has been identified as variable within A. barretoi specimens.
We report a new almost complete specimen of Araripemys, ventrally preserved on a
limestone slab from Crato Fm. It differs from general A. barretoi morphology, displaying an
ovoid-shaped and elongated carapace; elongated cervical vertebrae; pointed rostrum and
slender xiphiplastra.
If further analyses validate these differences in the future (eg. morphometric analyses),
we suggest that a new species of Araripemys should be erected, based on this new specimen.
Because the holotype of “A. arturi” would still not be distinguished from A. barretoi but
neither from this specimen, we suggest it should be regarded as Araripemys sp.
and implications for the origins of snakes
the origins of this remarkable diversity are poorly understood. Two-legged snakes have
previously been described, but snakes with four limbs have remained unknown— until now.
Tetrapodophis amplectus, a new snake from the Early Cretaceous (Aptian) Crato Formation
of Brazil, represents the oldest definitive snake and the first known with four limbs.
Tetrapodophis shows numerous derived features of snakes, including hooked teeth
implanting into sockets, an intramandibular joint, zygosphene-zygantrum articulations
between vertebrae, >150 presacral vertebrae, and transverse belly scales. Although snake-like
in most features, Tetrapodophis retains short but well-developed arms and legs. Adaptations
for aquatic life are not evident. Instead, Tetrapodophis exhibits specializations for burrowing,
supporting a subterranean, burrowing origin of snakes. Surprisingly, the limbs are not
vestigial but are instead specialized for grasping. Along with a highly flexible spine, here
interpreted as an adaptation for constriction, recurved teeth, and perhaps most striking, the
presence of a vertebrate in the gut, this suggests that early snakes preyed on vertebrates.
Finally, Tetrapodophis provides new insights into the geographic origin of the snakes.
Tetrapodophis, along with a high diversity of basal lineages from Africa and South America,
both extinct an extant, provides strong evidence that crown Serpentes originated and radiated
in Gondwana during the Early Cretaceous. They were part of a unique herpetofauna,
dominated by snakes, sphenodonts, and notosuchians, that evolved following the isolation of
Gondwana and Laurasia in the Jurassic.
representing a new genus and species of basal neotheropod dinosaur from the
Triassic/Jurassic boundary beds of South Wales is presented.
Its occurrence close to the base of the Blue Lias Formation (Lower Jurassic, Hettangian)
makes it the oldest known Jurassic dinosaur and it represents the first dinosaur skeleton from
the Jurassic of Wales.
The specimen retains plesiomorphic characters which it shares with Tawa and
Daemonosaurus, including three teeth in the premaxilla making its phylogenetic placement
problematic. A cladistic analysis of 366 characters for 46 taxa resolved Neotheropoda, with
Tawa hallae as its sister taxon and placed the new Welsh dinosaur as a basal member of
Neotheropoda. The “coelophysoids” Liliensternus liliensterni and Zupaysaurus rougieri are
now successive sister taxa to crown group neotheropods, making Coelophysoidea
synonymous with Neotheropoda. The new dinosaur is recovered as the sister taxon to
“Syntarsus” kayentakatae and all other coelophysids. Coelophysidae is supported by 3
synapomorphies (15 in the bootstrap) and Neotheropoda is supported by 23 synapomorphies.
The bootstrap results demonstrate that although Neotheropoda is well supported, the basal
part of the group is not. In our bootstrap tree the new welsh dinosaur, Liliensternus
liliensterni, Zupaysaurus rougieri, Dilophosaurus wetherelli and Cryolophosaurus ellioti are
found in a polytomy with the remaining clades of Neotheropoda; Coelophysidae and
Ceratosauria.
and non-rodent diprotodonts
enlarged and continually growing upper and lower incisors, termed diprotodonty, separated
from a highly reduced posterior dentition by a large diastema. While diprotodonty is present
in all living and extinct rodents, it has independently evolved in a phylogenetically diverse
range of non-rodent therian mammals, including hyraces and lagomorphs as well as
individual species of marsupials (the common wombat) and primates (the aye-aye). Here we
examine whether the independent evolution of diprotodonty across therian mammals is
limited to the dentition, or if it constrains the disparity of the whole masticatory system.
Three-dimensional landmarks were collected from virtual models of the cranium and
mandible of rodent-like diprotodont specimens and taxa representing the main extant rodent
families. Geometric morphometrics methods were used to examine the convergence between
the rodent and non-rodent specimens. The taxa in this study samples large phylogenetic
distances, however in both the cranium and mandible morphospaces all taxa group very
tightly together. Within the rodents, taxa from the main groupings based on masticatory
musculature (hystricomorphs, myomorphs, protrogomorphs and scuiromorphs) form discrete
groupings in cranial results. Partial least squares (PLS) show a high level of covariation
between cranium and mandible in all taxa. The findings of the study clearly demonstrate that
convergent evolution of morphology in diprotodont mammals is not restricted to the
dentition, but is also found in the cranium and mandible and their pattern of covariation. This
indicates that there are strong functional constraints on the masticatory system associated
with diprotodonty.
Romanian azhdarchids include the long-necked, mid-sized Eurazhdarcho as well as a relatively short-necked, mid-sized taxon (estimated wingspan 3.5-4 m). An enormous 7th or 8th cervical vertebra, giant proximal syncarpal, and section of mandibular symphysis are referable to Hatzegopteryx, described from the Densuş-Ciula Formation of the Haţeg Basin. These remains reveal proportions consistent with the other material of this taxon. Hatzegopteryx was a short-necked, robust-skulled azhdarchid, likely with an ecology and lifestyle different from that imagined for slender-necked, slender-jawed taxa.
Theropods are rare in these assemblages but the absence of large taxa appears genuine. Balaur bondoc was described as a velociraptorine but re-evaluation reveals its unusual features (including a fused carpometacarpus, reduced third finger, long hallux, laterally bowing pubic bones, and backswept pubes and ischia) better support placement within Avialae, specifically within a grade of Jeholornis-like avialans. The status of several more poorly known Romanian maniraptorans (Elopteryx, Heptasteornis and Bradycneme) is uncertain.
Several squamates are known from the Romanian Maastrichtian, including borioteiioids and snakes. The partial skull of a large heterodont lizard, estimated to have had a precaudal length of 475 mm, represents a new taxon under description. This animal is significant in being ‘intermediate’ in body size and ecology between smaller squamates and small dinosaurs.
What was it about pterosaurs that enabled them to reach these extraordinary sizes and were they up against the limits to size? Most maximum size estimates for birds and pterosaurs have compared power required with power available, making predictions from the cross-over between these variables. This approach is subject to great uncertainty since the trends are only weakly convergent, so small differences in assumptions can have large effects on the results.
There is more to flying than having adequate steady power. An animal must have sufficient power to leave the ground and climb until it can find rising air, then be able to land without injury. Its wing structure must be sufficiently stiff to support the aerodynamic loads of flight and its morphology must remain aerodynamically efficient in the face of allometric dimensional requirements.
Consideration of these different potential limits throws new light on why pterosaurs were truly the “all time giants of the air” and points to take-off and landing as being the most likely limits to their size, rather than power availability or structural strength.
carnivorous mammals
limited preserved skeletal material. By determining the relationship between form and
function in living animals, it is possible to create a model for testing mode of locomotion in
extinct forms. The calcaneum is known to be informative in terms of mammalian locomotion,
but there is a still a lack of data for many extant carnivorans. Empirical data from extant taxa,
for which locomotion can be reliably documented, is necessary to make informed assertions
about the locomotion of extinct taxa.
We took linear measurements and 2D landmark data from 69 extant Carnivora to
generate a comprehensive morphological dataset. We carried out multivariate analyses to
identify locomotor groupings based on calcaneal morphological characteristics. We then
added 48 fossil taxa to determine their probable locomotor mode. We explored the influence
of phylogeny through phylomorphospace using maximum-likelihood phylogenetic models,
and carried out an ancestral state reconstruction using the extant taxa.
We distinguish distinct morphospace occupation for different locomotor groupings in
extant taxa, particularly arboreal and semi-fossorial versus terrestrial and cursorial. The
length of the calcaneal heel versus calcaneal foot, the width of the calcaneum, and the shape
of the calcaneal foot itself reflect the biomechanics of different locomotor modes, and serve
as indicators for locomotor grouping among Carnivora. Our analysis supports an arboreal
locomotor mode for the early carnivoran Dormaalocyon latouri, and a more arboreal mode
for Nimravidae, while early canids occupy a distinctly different morphospace from their
extant relatives, reflecting their arboreal origins.
We discuss a new ankylosaur discovered in 1994 in the Wessex Formation at Chilton Chine, Isle of Wight. This partial skeleton (including limb and limb girdle elements, vertebrae and osteoderms) is one of the most complete ankylosaurs ever found in the UK and has the potential to resolve many questions about these dinosaurs. It has been provisionally referred to P. foxii but differs in several respects from the holotype and referred specimens of this taxon.
Each bone has been recorded using photogrammetry and we have reconstructed the skeleton in 3D. The histology of the sacral shield shows a plywood-like structure with extensive, well ordered structural fibres, in contrast to previously reported Polacanthus specimens. Initial findings suggest that the specimen represents a new taxon. Its implications for Early Cretaceous ankylosaur diversity and taxonomy will be discussed.
general, the vertebral column has been underrepresented in the morphological and
biomechanical literature. Moreover, the vertebral column is often treated as one functional
unit, with few studies considering the complexity and regionalisation of this structure in
detail.
Here we report the results of both linear and 3-dimensional analyses of vertebral
column shape using 22 and nine living species of felids, respectively, to assess whether
ecological specialisations have significantly influenced the evolution of vertebral
morphology.
Principal components analysis (PCA) of all log-transformed linear variables (e.g., centrum
length) showed significant separation of species based on locomotory specialisations.
Additionally, shape was more strongly influenced by size in the anterior vertebrae (cervicals
and thoracics) than in the posterior (lumbar) vertebrae.
16 3-dimensional landmarks representing the full post atlanto-axial pre-sacral
vertebral column of ~100 specimens were analysed with both PCA and Phenotypic
Trajectory Analysis (PTA). Again, anterior and posterior vertebrae showed different results,
with a stronger niche specialisation signal, both for locomotory (explaining 5.4-17%
variance) and prey size groups (3.5-17.5%) observed in the posterior region, where the
influence of size was also stronger (3-14%). PTA results also demonstrated that shape
differences among ecological groups were concentrated in T10, L1, L4, and L7, and that
these are not significantly correlated with phylogenetic relatedness.
Lastly, scaling analyses showed that ecological groups exhibit distinct shape-size
allometries, with cursorial (cheetah) and scansorial taxa showing similar slopes, distinct from
arboreal and generalist terrestrial taxa.
A good fossil record allows tracing antler diversity back to the early Miocene (≈ 20 mya). These early antlers of stem cervids share the fundamental apophyseal, branched, and deciduous condition with those of extant deer, but differ in morphology by being simpler structured, lacking a beam construction, with a variety of basic architectures (palmate, dichotomous, bi- to multi-pointed plate- and crown-like).
Previous studies used transversal thin-sections to study antler histology in early deer and inferred on their growth modi. The results pointed to substantial physiological differences leading either to autotomy of still living antler-tissue, inverse ossification before antler sequestration, as well as irregular shedding and indicated evolutionary development in fundamental processes of the antler cycle. To test the previous hypotheses we used x-ray µ-CT for displaying internal bone structure across the entire antler of a larger selection of early deer and compared them among themselves and with those in living deer.
Our preliminary results include the absence of arrested growth lines, a longitudinally arranged vascularisation and lack of secondary erosional structures, what lead us to conclude on early antlers as quickly growing, short-lived organs. Moreover, we did not find support for sequestration of living antlers. If this then necessarily implies the context of a regular antler cycle comparable to that in extant deer needs further investigation at the histological-physiological level. However, there is evidence for the existence of fundamental processes in antler development (intrinsically induced cyclic necrosis, sequestration, and regeneration) from the earliest record of antler evolution onward.
the most devastating mass extinction events. It is universally accepted that this impact led to
the extinction of all non-avian dinosaurs. However, whether dinosaurs were reigning strong
right up to the impact, or were on the decline for a long time prior to it, has been the subject
of decades of debate. Here for the first time, we explicitly account for shared ancestry as
implied by the dinosaurian phylogeny, to answer this long standing question. We study the
patterns of speciation and extinction (speciation dynamics) over 170 million years from
dinosaur origins to the K-Pg boundary using a Bayesian phylogenetic regression model. We
find overwhelming evidence that dinosaurs were in decline - with the rate of extinction higher
than the rate of speciation - tens of millions of years prior to the end of the Cretaceous. This
pattern remains true in the three main dinosaurian clades, Ornithischia, Sauropodomorpha
and Theropoda, and highlights that Mesozoic dinosaurs showed a marked reduction in their
ability to replace extinct species with new ones, making them vulnerable to extinction and
unable to respond quickly to and recover from the catastrophic event.
The foramen has been identified as a major landmark on the humeri of tetrapodamorphs and its relative position is thought to have changed little during the early evolution of the tetrapod forelimb. In most stem tetrapods the foramen pierces the entepicondyle enabling the artery and nerve to pass through the humerus from the dorsal to the ventral surface. Recent re-examination of the humerus of the Devonian tetrapod Acanthostega revealed that it lacks this morphology. Instead, the foramen is restricted to the ventral surface where it passes through the ventral ridge. The origin of the condition seen in most tetrapods appears to be linked to twisting of the humerus. This rotated the distal end relative to the proximal end, and allowed the manus to be placed on the ground during locomotion. Twisting resulted in the artery and nerve now passing through the entepicondyle producing the characteristic foramen. New material from the early Carboniferous of Scotland shows an intermediate condition between Acanthostega and typical forms, in which the foramen pierces the medial edge of the condyle and exits on the ventral surface. These observations have led us to re-assess the homologies of the tetrapodomorph forelimb.
Does this pattern represent a true decline in disparity and diversity through time, or a more complex sequence of shifts within the group?
Here is presented a comparison of evolutionary rates among crown- and stem-group Crocodylomorpha in relation to morphospace occupation. The phylogenetic framework of these analyses is a new phylogeny of the Crocodylomorpha assembled using the Matrix Representation Parsimony (MRP) method.
This study finds support for extreme evolutionary stasis in several crocodylomorph clades. Diversity among the Crocodylomorpha appears to be closely linked with temperature, with decreasing diversity in the Cenozoic closely matching global cooling. Additional morphospace occupation by stem-group Crocodylomorpha relative to the crown-group is occupied by taxa originating from two discreet adaptive radiations in the mesozoic, with disparity otherwise remaining constant throughout the Mesozoic and Cenozoic.
their diplodocine relatives, but are generally more robust. Apatosaur necks are much thicker
than in other sauropods: cervical ribs and their supports are uniquely robust, and the ribs are
strongly displaced ventrally. The diapophyseal and parapophyseal rami therefore project
ventrolaterally, so that the neck would have been subtriangular in cross-section, not tubular.
Why did apatosaurines evolve necks that were apomorphically expensive to build, maintain,
and operate? While sexual selection is not a convincing explanation for the evolution of
sauropod necks in general, several features of apatosaurine necks suggest adaptation for
combat:
1. Ventral displacement of cervical ribs improved the lever arms of the hypaxial muscles,
strengthening ventral neck movements.
2. Ventrolaterally directed parapophyseal rami were oriented to resist ventral impacts.
3. The ventral trough between the cervical ribs provided soft-tissue protection for the
trachea, oesophagus, and major blood vessels.
4. The ventrolateral processes on the cervical ribs may have been bony clubs, bearing
thickened pads of connective tissue or keratinous knobs or spikes.
These adaptations suggest a style of combat in which the neck itself was crashed down or
sideways into the opponent, rather than giraffe-style combat in which the head is the weapon.
The closest extant analogue may be the elephant seal Mirounga: males fight by crashing their
necks and anterior thoraxes together. As with apatosaurs, their cervical vertebrae are more
robust than in relatives, and their ventral processes more pronounced; but enormous softtissue
padding makes the analogy very inexact.
We performed a photogrammetric scan of the bones and digitally manipulated the virtual skeleton to find the osteological limits of motion imposed by these chevrons. In the first 20 caudal vertebrae, vertebrae pairs may deflect for up to 20º before osteological stop in extension and 8-10º in lateral flexion, suggesting the in vivo dorsal and lateral range of motion was limited rather by soft tissue. Flexion is limited by the rather large chevrons, which contact with less than 5º of deflection. The motion in the distal region is dorsoventrally limited, as in other taxa with overlapping chevrons (dromaeosaurids or ankylosaurids).
Additionally, the hypaxial caudal region of Spinophorosaurus is greatly developed: the anteriormost chevrons are very elongated and the anteriormost transverse processes are dorsally elevated and angled, indicating powerful hypaxial muscles. Also, the first twenty caudals become progressively elongated, as in diplodocids.
An analysis in progress of the dermal ossifications originally proposed as a thagomizer suggests they are not osteoderms at all, thus there is no evidence for such thagomizer. However, the limited proximal flexion, powerful hypaxial musculature, elongated caudal vertebrae and the overlapping chevrons appear to be a single, perhaps incomplete, functional complex of unclear function.
rosse", Late Miocene; Moncucco Torinese, latest Miocene; Cava 6 near Orosei, Pleistocene;
Valdemino Cave, Middle Pleistocene; K 22, Middle-Late Pleistocene; San Teodoro, Late
Pleistocene. Remains comprehend maxillae, frontals, dentaries, indeterminate tooth-bearing
bones, vertebrae and humeri.
After a comparative analysis of cranial bones of the four extant species of European
gekkotans (Euleptes europaea, Hemidactylus turcicus, Mediodactylus kotschyi and Tarentola
mauritanica), maxillae and frontals turned out to be the most informative among Italian fossil
findings, whereas dentaries and tooth-bearing bones are less useful. Such comparative
analysis has not been carried out on postcranial skeleton so far.
Using the newly identified diagnostic features, fossils have been referred to Euleptes sp.
(Gargano), cf. Euleptes sp. (Moncucco), Hemidactylus cf. H. turcicus (Valdemino),
Tarentola mauritanica (K 22) and Gekkota indet. (San Teodoro). Remains from Cava 6 and a
frontal from K 22 have not been studied yet.
Firstly, palaeoart is rife with copying and plagiarism. Many commissioned palaeoartworks replicate elements or entire compositions from existing works to breach copyright law; perpetuate errors and outdated ideas; deny recognition and financial reward to original artists; and drown out new styles and approaches to fossil animal restoration with artistically homogenous work. Secondly, the scientific rigour associated with many palaeoartworks, even those produced in close association with consulting academics, is often low. We ascribe this to laissez-faire attitudes from some consultants, underestimation of the educational value and influence of palaeoartworks, as well as poor utilisation of the existing pool of demonstrably qualified palaeoartists. Thirdly, many palaeoart patrons have unrealistic concepts of financing artwork, often offering little or even no recompense to artists because of financial restrictions associated with their own projects. We hope that bringing these issues to wider attention will raise support from individuals involved with palaeoart production and help bring real change to industry practises
Cenozoic
always shown such high levels of ecomorphological disparity. Mesozoic mammals are
stereotyped as small ‘generalists’ or ‘insectivores’, only evolving novel forms as a result of
an adaptive radiation at the K-Pg boundary. Shifts in the disparity of phenotypic traits in
mammals from the Mesozoic to Cenozoic are not well quantified. Complicating matters is an
emerging picture of surprisingly high levels of morphological disparity in Mesozoic
mammals. In an attempt to better constrain patterns of mammal diversification, we
quantified ecomorphological disparity in two Lagerstätten stratigraphically flanking the
KPg boundary: the Cretaceous Jehol Biota, and the Eocene Messel pit. These sites were
selected due to their common lacustrine setting, as well as the relative abundance of
specimens yielding information on anatomical systems beyond dentition. Functionally
relevant continuous measurements were collected for limbs and jaws to represent locomotion
and feeding type respectively. Preliminary results show that mammals from these two sites do
not show substantial differences in disparity in traits related to feeding ecology. The Jehol
mammals do occupy a marginally smaller amount of functionspace, but overlap almost
completely with the Messel mammals. In terms of diversity of locomotor structures, the Jehol
mammals again overlap with the Messel mammals but occupy a smaller region of
functionspace. The elevated disparity of Messel can be attributed to a handful of groups with
locomotor ecologies unknown from the Cretaceous: bats, early horses, and the genus
Leptictidium, which may have been semi-bipedal.
large scale collection projects
(NHMUK), London undertook four digs to Woodeaton Quarry, Oxfordshire, a designated
SSSI, to collect sediment to sample for microvertebrates.
Woodeaton Quarry is important as it exposes one of the most complete sections of the
middle and upper Bathonian in southern England, spanning from the top of the Taynton
Limestone Formation (Great Oolite Group) to the lower part of the Forest Marble Formation
(Great Oolite Group).
Over the course of our trips approximately 6.5 tonnes of sediment was collected,
washed and sieved. The residue was then separated into different size fractions and
examined. Due to the amount of material to curate, a team of volunteers were selected to
assist with identifying and sorting the material into broad taxonomic groups (fish, mammal,
amphibian, reptile and invertebrates) these are then shown to specialists within the Museum
for further identification. This occurs behind a window in the collections area viewable from
the public galleries with a microphone and monitor, so we can engage the public with current
research ongoing within the NHM and discuss the project. To assist with identifications and
future work, we are putting together a guide with descriptions and images.
Woodeaton Quarry offers the chance to provide some unique insights into the small
vertebrate diversity of the upper Bathonian. Studies are currently underway focusing on the
biostratigraphy, palaeoenvironments and taxonomy.
Keuper levels (Carnian) of the locality of Manzanera (Teruel Province, Spain). These fossils
belong to different tetrapod clades. The detailed study of abundant material, including
numerous unpublished specimens, allows us to modify and extend the previously proposed
faunal list of this locality. The remains assigned to nothosauroids consist of several vertebrae
and ribs. Their previous attribution to Nothosauria is refuted, based on the presence of
infraprezygapophyses and infrapostzygapophyses in the neural arches. Within
sauropterygians these characters are only present in the nothosauroid Simosaurus gaillardoti
and the pistosauroid Bobosaurus forojuliensis. The morphology of the vertebrae and the
presence of distally expanded ribs suggest that the remains from Manzanera could belong to
Simosaurus, a taxon so far not recognized in the Iberian record. There are placodont elements
that consist of several isolated osteoderms of the carapace of cyamodontoids. Two isolated
osteoderms have the same features of those of the placochelyd Psephoderma. Another
osteoderm similar to those that conform the dorsolateral ridge in Psephosauriscus mosis is
also identified. Several partial vertebral centra from the caudal region of ichthiosaurs are also
recognized. The disc-like shape of the centra is a derived condition that is not present in the
basal forms of ichthyopterygians. These elements represent the first record of Ichthyosauria
in the Iberian Keuper, constituting the second reference to this group in the Iberian Triassic.
The faunal list from Manzanera also includes temnospondyls, represented by fragmentary
cranial remains.
Greenland
Obrutschew Bjerg Formation on Celsius Bjerg, Ymer Ø, East Greenland. The Obrutschew
Bjerg palaeoenvironment was a deep, wide, long lived and stratified lake and its age is
exactly Devonian-Carboniferous boundary. The palaeogeographic location is in the heart of
the ORS Continent and, as such, the shark must have accessed the lake via its discharge to the
sea. It was probably feeding on the palaeoniscid Cuneognathus, which was about the only
other fauna within the lake.
The shark (anterior half only) is quite unusual in that it preserves some 50 teeth
together with a dorsal fin spine. It can be attributed to Cladodoides, a genus hitherto only
known from isolated teeth. This means that, on the basis of the spine, Cladodoides can now
be attributed to the ctenacanths.
Rhinochelys
adaptations for marine life. Here, we present CT-based reconstructions of the cranial
endocast, inner ear, and carotid circulation of the early sea turtle Rhinochelys, and offer
comparisons to fossil and modern sea turtles. As in other sea turtles, the cranial endocast of
Rhinochelys is tubular. The cephalic flexure is poorly marked, and the cerebral region is
transversely weakly. Unlike in Plesiochelys, but as in modern sea turtles and Puppigerus, the
medulla oblonga is located beneath the level of the olfactory tract. Olfactory lobes are,
similar to modern sea turtles, smaller than in Plesiochelys or Puppigerus. The sulcus
olfactorius is ventrally closed in its anterior part, a feature unknown in other fossil or extant
sea turtles. The foramenorbito-nasale is small, and the nasal capsule large. A large, oval
trigeminal foramen is bordered by the pterygoid, prootic, and parietal. An epipterygoid could
not be discerned. The stapes is more strongly curved than in Plesiochelys. Instead of being
completely surrounded by bone, the fenestra ovalis is ventrally open between the opistothic
and prootic. Semicircular canals are thicker than in Plesiochelys, and, as in Puppigerus, the
common crus is dorsally markedly concave. Carotid arteries are discernable as canals largely
confined to the basisphenoid. The comparisons presented show that neuroanatomy is
disparate in early sea turtles, and needs to be examined further and in a (pending)
phylogenetic context to understand the sensory evolution in the group.
from the Crato Formation (Cretaceous, ?Aptian) of Brazil
described from the ?Aptian Crato Formation (Araripe Basin) of Ceará, North East Brazil. The
material comprises of post cranial remains, including an articulated sequence of thoracic
vertebrae, a disarticulated pair of sacral vertebrae, partially complete forelimbs and
hindlimbs, and several disarticulated osteoderms. This is the first occurrence of the hindlimbs
of Susisuchus preserved in association with diagnostic material, providing new anatomical
details for this mesoeucrocodylian.
Soft tissue preservation is also reported for the specimen. Details of the dorsal shield
are preserved as an external mould showing the tetraserial paravertebral arrangement of body
scales and a cast of the soft tissue surrounding the left hindlimb. Soft tissue preservation has
been reported for Susisuchus previously but this is the most extensive and detailed soft tissue
reported so far. The scales are preserved as external moulds (impressions of some authors)
while soft tissues of the hindlimb appear to have been mineralised.
The Oxford Clay Working Group (OCWG) was set up in 2011, in collaboration with the quarry owners, to collect, protect and document vertebrate fossils from this very important resource. Despite collecting unassociated fossils, particularly teeth and isolated bones, efforts to secure articulated or disarticulated skeletons have been hampered by modern quarrying techniques and a change in working practice in excavating to the most productive levels.
Here we report on a newly recovered, partially articulated plesiosaur skeleton representing a fully mature individual, which was saved because of the combined efforts of the OCWG in conjunction with both the quarry owners and employees.
The specimen, which has been safely conserved and secured by the group, will be deposited into an accredited institution and so made available for scientific study and, perhaps, public display. It is planned that the skull block is CT scanned which may not only provide hitherto unknown data relative to Plesiosauroidea but may help, together with other skeletal elements, to solve anatomical and taxonomic problems within Cryptoclididae and, perhaps, Elasmosauridae.
recorded in the Tertiary. The records are mainly from the Eocene, and more abundant in the
‘North Sea Region’ in Early Eocene, as for instance the large Danish forms. They are also
found in late Early Eocene in London Clay, in Late Eocene in Caucasia, and in Miocene of
SE-Asia, although none were described from the famous Bolca fauna (early Mid Eocene).
However, there is a large, still undescribed ‘tarpon-like’ fish in the Bolca Museum (obs.
MCL & NB 2014). There are even fewer described from the long Cretaceous period, 4-5?
genera, including the large Paraelops from Romualdo Formation, Araripe Basin, NE-Brazil,
and a large undescribed megalopid from Tlayua, Pueblo, Mexico, both ‘Mid Cretaceous’. The
oldest elopiforms are from Late Jurassic Solnhofen Limestone.
The large Danish ‘tarpons’ come from ‘cementstones’ in Fur Formation (earliest
Eocene, ca 55 m.y.), and here we report an almost complete specimen which is c. 110 cm
long; however, big isolated scales found in this formation indicate fishes at least twice as big
(comparable in size with the living Tarpon atlanticus - over 2½ m). This specimen has a
heavy skull lacking the lower jaw, and is preserved in 3-D. It was split in the midline and acid
prepared, being then CT-scanned in Aarhus and reconstructed in Lab. Biol. Anthropol.,
Copenhagen University to attempt precise, detailed comparisons with modern skulls and with
the 3-D skulls preserved in concretions from the London Clay.
filled by sharks, whales, teleosts, among others. In particular, the pachycormid pioneering of
the large (>1 metre length) vertebrate suspension-feeding niche has attracted attention as an
indicator of a major change in planktonic populations in the Jurassic. The 19th century
Jurassic genera of Leedsichthys and Asthenocormus were recently supplemented by the
Callovian Martillichthys, and the recognition of the Cretaceous suspension-feeder
Bonnerichthys (often misidentified as specimens of the pachycormid carnivore
Protosphyraena) extended this clade to the end of the Mesozoic. New specimens of the
suspension-feeding pachycormid genus Rhinconichthys (erected on the basis of material
collected by Gideon Mantell) from North America and Europe provide information on the
development of this edentulous suspension-feeding tribe. In conjunction with re-examination
of the type material, this taxon provides new information on oral specialisations utilised by
this group in order to dominate suspension-feeding in the Jurassic and Cretaceous.
Transition, although their precise position in this hierarchy has been fought over for some
years. Discoveries in the last three years have expanded our global knowledge of the
diversity, distribution and success of this group, continuing the recent 'Pachycormid
Renaissance'. However, clarity over the definitions of pachycormid taxa has been undermined
by the number of type specimens destroyed during World War II, introducing a need for
neotype material to be identified (e.g. Asthenocormus titanius, Hypsocormus macrodon), and
comparative work has revealed how poorly constrained a number of historical genera are,
particularly those of the Toarcian (Early Jurassic) Holzmaden shale fauna that were the
foundation of Arthur Smith Woodward's family Pachycormidae in 1895. These historical
problems with descriptions and material have undermined confidence in recent phylogenetic
analyses. The characteristic unusually long pectoral fins appear to have developed in
conjunction with otherwise reduced skeletal ossification to counteract buoyancy problems in
a group lacking a gas bladder. A sample of over 90 specimens from 16 recognised
pachycormid genera was assessed, demonstrating that the ubiquitously stated 'scythe'-like
pectoral fin is not a pachycormid synapomorphy: three clear and distinct pectoral fin
structural morphotypes emerged, reflecting a diversity of pachycormid lifestyles that changed
throughout the Mesozoic, from agile pursuit predator to slow-cruising suspension feeder.
Those morphotypes closely mirror modern fuel-saving wingtip designs from today's
aerodynamicists, converging on similar solutions to these enigmatic and fascinating fish some
160 million years later.
Formation of Yunnan Province, China
associated with Hettangian (Early Jurassic) prosauropod remains from Lufeng County,
Yunnan Province. Both were recovered from the 'Lufeng Formation', now restricted to the
unit previously known as the Lower Lufeng Formation or Series. Within this revised
nomenclature, the formation consists of two subunits: the older Shawan Member and the
younger Zhangjia'ao Member, representing the former 'Dark Purple' and 'Deep Red' Beds,
respectively. A prosauropod specimen (three closely associated sequences of articulated
vertebrae) was recently recovered from near DaWaShan, one cervical displaying localized
brittle deformation. Within 200 mm of this vertebra, parts of five teeth were recovered, one
fitting well in one of the brittle deformation recesses, interpreted as a bite mark. A further
sauropodomorph referred to Yunnanosaurus was excavated from the Shawan Member at
Qingliangshan, three shed theropod teeth being recovered from among its pelvic elements,
matching Sinosaurus triassicus and ranging from 25-30 mm in crown height. Morphometric
analyses plot these teeth distinctly from those of other theropod taxa, with an unusually low
crown angle (50-64°) for the 15 mm crown base length. The teeth also feature an unusually
high denticle density on the distal carina, producing a particularly low denticle size difference
index (0.62-0.88), supporting the transfer of the material out of Dilophosaurus, and
suggesting an unusual functionality. The DaWaShan teeth are not as well-preserved, but their
form is clearly distinct from Sinosaurus triassicus and all other theropod taxa known from the
Lufeng fauna.
morphometric approaches
frequently used in comparative morphological studies, often including extant and extinct
taxa. Locomotion is an important function in the ecology of animals, and adaptations to the
under-foot substrate are to be expected. Here we present a pilot study testing the ability of
morphometric analyses to differentiate between morphologies adapted to different under-foot
substrate compliances (dry grassland, compliant wetland and rocky desert/mountain). We
hypothesised that species naturally inhabiting areas with firmer substrates will have shorter
and thicker distal limb elements to better withstand bending moments. To test this we
assessed the 3-dimensional morphology of the third metacarpal (Mc3) of a range of living
and extinct perissodactyls (odd toed ungulates; 108 specimens representing 33 species) using
both traditional linear metrics and 3D geometric morphometric landmarks. Traditional
metrics were corrected for size effect of length measures using regression analysis, and the
residuals were used as shape data. All analyses were assessed in a phylogenetic framework.
Strong size and phylogenetic effects were found in both analyses. Results suggest that 3D
landmark analysis of the Mc3 cannot distinguish between substrate types. Traditional metrics
detect significant differences between substrate types along the first principal component;
shape changes recorded are heavily influenced by depth measures of the Mc3 shaft,
supporting our hypothesis. To explore the link between Mc3 shape and substrate type further,
we suggest using a combination of landmark data and traditional metrics on a larger dataset.
The systematic revision of Spinophorosaurus is in progress, and preliminary results place this
taxon within Eusauropoda. One of the most peculiar features of this sauropod was to have
spike-bearing osteoderms placed in the distal tail region. Indeed, this feature was used to
formulate its generic name. However, herein, we provide a detailed description for these
structures providing a new anatomical interpretation.
Two spine-shaped elements (HB64M) were found in association with the scapular
girdle (two scapula and a coracoids in articulation) and displaced from its anatomical
position. These structures present a triangular to “L-“shaped morphology in internal and
external view with a convex external and a concave internal faces. The base of the “L” is
expanded and bears a D-shaped cross-section. The distal end of “L” short branch has a rough
articular surface in the internal side. The long branch is lenticular in cross-section and bears a
longitudinal wide crest in both sides. The outer side of the “L” also bears an important rough
surface.
This morphology was considered to be similar to caudal spikes found in some
Chinese sauropods suggesting that they might correspond to caudal spikes osteoderms. These
of elements are scarce in the sauropod record and some authors have discussed the previous
interpretation. The bones have been recently prepared. Now, a full description of these
elements supports its reinterpretation as clavicles. The Spinophorosaurus clavicles are thicker
and bear deeper internal surface than in basal neosauropods.
Spinophorosaurus nigerensis (Niger, Middle Jurassic)
similarities with mamenchisaurids. The systematic revision is considering a new phylogenetic
position, within Eusauropoda. The exceptionally preserved axial skeleton of
Spinophorosaurus is important to understand the variability of several characters along the
series and it is important for the establishment of new morphological characters. Some
aspects of the cervical vertebrae morphology along the cervical series are discussed as well as
the laminae pattern. The laminae pattern is conservative along the cervicals, with welldefined
podl, prdl, spol, sprl and short acdl and pcdl. The position and orientation of laminae
are mainly controlled by morphological changes in the spine. The presence of a posteriorly
projected tpol might be exclusive of Spinophorosaurus and a convergence with some
euhelopodids.
Other exclusive features in Spinophorosaurus cervicals were proposed: i) anterior
cervicals with accessory anterior processes on prezygapophyses; ii) triangular posterior
processes on diapophyses; and iii) enlarged triangular cervical epipophyses, posteriorly
directed. The former feature is more pronounced in mid-posterior cervicals bearing a striated
surface for the attachment of the Mm. ascendens cervicalis and Mm. longus colli dorsalis.
Epipophyses is prong-shaped (as in Jobaria and Euhelopus), and is round and stout on
posterior cervicals. The triangular posterior process of diapophyses becomes prominent from
middle cervical vertebrae and sometimes bears striated surface probably for Mm.
intertransversarii attachment. Some of those features are present in a partial neck of a
probable juvenile of Spinophrosaurus, while the absence of some characters may be
attributed due ontogeny.
eusuchian crocodyliform from the Late Cretaceous of Lo Hueco (Cuenca, Spain)
(Cuenca, Spain) are abundant and comprise cranial and postcranial elements, as well as
numerous isolated teeth. This material allowe to identify two morphotypes of non-Crocodylia
eusuchians, both with features suggesting a close phylogenetic relationship with the genus
Allodaposuchus. The morphotypes from Lo Hueco show remarkable differences between
them, being recognized as belonging to two taxa.
The first taxon was recognized as a new medium sized crocodyliform, with a
relatively wide and rounded rostrum. It has large teeth, separated by small interalveolar
spaces. The second taxon, presented here, is also a medium size crocodyliform. It can be
distinguished from the former taxon by the presence of a more elongated and thinner rostrum.
This second crocodyliform from Lo Hueco presents a unique combination of characters
within Eusuchia, including a peculiar dental occlusion between maxilla and lower jaw, the
presence of lateral projections of the palatines over the suborbital fenestra, a sagittally
septated choana, and an exclusive morphology of the anterior palatine process. Therefore, it
is recognized as a new form. Its inclusion in a phylogenetic analysis placed it within a
monophyletic group that consists of the type species of Allodaposuchus and related taxa.
Given these results, a new hypothesis about the paleobiogeographical distribution of the
representatives of this clade is here proposed.
Hueco (Fuentes, Cuenca)
attributable to titanosaur sauropods. Among them, a high abundance and morphological
disparity of appendicular bones is recognized. Most of this appendicular material is partially
or totally disarticulated. In addition, several specimens lack the proximal or distal ends. These
features make difficult its association with other bones corresponding to the same titanosaur
individuals, and also its taxonomic assessment. The study of a sample composed by several
femora and humeri from Lo Hueco, attributable to titanosaur sauropods, is done through 3D
geometric morphometric techniques. It allows identifying two main morphotypes of each
category of bone. These results are consistent with previous studies on cranial elements, and
in a much more reduced set of femora. Principal Components also supports the differences
observed in several characters between both morphotypes.
A robust and anteroposteriorly compressed morphotype of femora is recognized. The
other one is a more slender type, with a high eccentric diaphysis. Concerning the humeri, a
more robust and a slender and elongated morphotypes are identified. The generation of mean
shape 3D models from the sample, related to each of the Principal component analysis
(PCA), allows to visualize some morphological differences comparing incomplete specimens,
related to the two morphotypes. For example, a difference is the presence of a more
quadrangular humeral head, with a high deltopectoral crest, in the robust morphotype; but a
more rounded humeral head, with a deep-ventrally directed stepwise deltopectoral crest, in
the slender morphotype.
the early Oligocene of Boutersem (Belgium)
collection of fossil vertebrate remains. They have been found in a fluvio-lacustrine complex,
the Boutersem Sand Member of the Tongeren Group. The information currently available on
this faunal assemblage is relatively good and allows a correlation with the reference level MP
21 of the mammalian biochronological scale for the European Paleogene. However, its turtle
fauna is unpublished. Several fossils of turtles from Boutersem are presented here for the first
time. Most of them can be assigned to a single form, represented by partial shells and isolated
plates, corresponding to several individuals. The only contemporaneous turtle taxon so far
recognized near Boutersem is Ptychogaster laurae, defined in the associated MP 21 locality
of Hoogbutsel. The turtle from Boutersem differs from Ptychogaster laurae, as well as from
all the representatives of Ptychogaster, by numerous characters, including: thinner plastron,
absence of long epiplastral lip in the sagittal plane, absence of long overlap of the pectoral
scutes on the entoplastron, absence of plastral hinge. This availability of characters is shared
with some members of other freshwater clade of Testudinoidea: the “Palaeochelys s.l. –
Mauremys group”. These and other characters (e.g. absence of lateral keels in the carapace,
trapezoidal morphology of the anterior plastral lobe, the observed contact between the gular
scutes and the entoplastron) are shared with Landreatchelys, a poorly-known and problematic
taxa identified in other European localities of the middle and upper Eocene (MP16 to MP18).
This systematic attribution is discussed.
Formation
now restricted to relatively warm regions, with a relative limited geographical distribution,
not including Europe. However, Pleurodira was a very successful group of turtles in Europe
during both the Upper Cretaceous and the Eocene. Two Gondwanan pleurodiran lineages,
belonging to Pelomedusoides, are identified in the European record: Bothremydidae and
Podocnemididae. The first was very abundant in the Upper Cretaceous of this continent,
being very scarce in the Paleogene record. Podocnemididae reached Europe in the Eocene. Its
Eocene record is abundant, including the members of the European genus Neochelys, as well
as several forms hitherto unpublished or poorly-known.
The so far described British Eocene record of turtles includes a valid member of
Pleurodira, Palaeaspis conybearii, from the lower Eocene of the London Clay (Isle of
Sheppey). Its systematic attribution is controversial, having been proposed as a member of
Bothremydidae by several authors.
A new shell, including the partial carapace and the almost complete plastron, is
presented here. It comes from Bracklesham Bay (Sussex), having being found in the Early
Eocene of the Wittering Formation (Bracklesham Group). Several characters (e.g. wider
neurals, more elongated plastron, deeper anal notch) do not allow its attribution to
Palaeaspis. This specimen could correspond to a podocnemidid. If this hypothesis is
confirmed, this finding would correspond to the first confirmed reference to Podocnemididae
in the British record. Its comparative study will include abundant unpublished information,
corresponding to specimens from several European countries.
paleobiogeographic implications
taxa of basal Eucryptodira. One of the worst-known clades is Thalassemydidae, exclusively
represented by the members of Thalassemys. The type species of Thalassemys, Thalassemys
hugii, has only been recognized in the Kimmeridgian of Solothurn. A second valid species of
this genus, Thalassemys marina, is exclusively represented by its type specimen, from the
Tithonian of Germany. The only known specimen of the genus Thalassemys outside Central
Europe was recently identified in Dorset (England), in Kimmeridgian levels of the
Kimmeridge Clay Formation. It was recognized as Thalassemys sp. A new British specimen
is studied here. It also comes from the Kimmeridge Clay Formation, but from Abingdon
(Oxfordshire). It preserves elements unknown on the British specimen previously assigned to
Thalassemys. The study of the Abingdon turtle offers new data on the intraspecific variability
of this poorly known coastal eucryptodiran member.
The specimen from Abingdon is identified as Thalassemys hugii. It shell corresponds
to the largest shell of a basal eucryptodiran turtle recognized globally. The identification of
Thalassemys hugii outside its type locality, and also outside Central Europe, shows that this
coastal turtle had a relatively large paleobiogeographical distribution. The specimen from
Dorset is recognized as belonging to a different species. The coexistence of two species of
Thalassemys in the same formation, and in the same country, is recognized for the first time.
In fact, only one species of Thalassemys had hitherto been identified in the Kimmeridgian
record.
The primary base for the collection was that of the former Newport Museum, which was bolstered by the collection of the Ryde Literary Society Museum sometime after its closure (prior to 1913). With the total closure of the Ventnor Museum in 1955 and the transfer of its specimens to the Council, the Museum of Isle of Wight Geology in Sandown became for a long time the only museum dedicated to the geological heritage of the Isle of Wight.
Over 50% of the current collection of Dinosaur Isle can be traced to transfers from one of these museums or from specimens collected by staff, with the rest of the donations being made by numerous collectors.
Although there have been many people who helped shape the museum into what it is today, a few key individuals played major roles in making Dinosaur Isle a success.
Despite the variability in patellar presence, it is generally assumed that the patella arose only once in the mammalian lineage. Until now, no formal scientific analyses have been performed to support this hypothesis. We ask: how many times did the patella evolve within the mammalian clade?
To address this question, we integrated data from literature and first-hand fossil/Recent specimen studies to reconstruct the evolutionary history of the mammalian patella. Instead of one patellar origin, we instead infer that this bone likely evolved around nine times in crown group Mammalia: in monotremes, in multituberculates, in symmetrodonts, in borhyaenoids, up to four times in marsupials, and finally in the ancestor of all eutherian (placental) mammals.
The reconstruction of trait evolution in mammals also allows us to predict the presence of the patella in fossils with incomplete hindlimb material. For example, because our reconstruction suggests the patella in eutherian mammals is very highly conserved, we expect it to be present fossil species like †Protoungulatum and †Miacis, for which there are currently no known reports of the patella.
ankylosaur pelvic shields. Here we report an unusual feature present across the pelvic shield
of a well-preserved ankylosaur from the Isle of Wight, southern England, and discuss its
structure, functional implications and usefulness in determining phylogeny. Originally
thought to be Polacanthus foxii, this new ankylosaur specimen has yet to be described and is
considered nodosauroid (indet.). The pelvic shield exhibits alternating light and dark layers at
the macro-level, revealed by histological analysis as a plywood-like structure, each ply being
rotated at approximately 90° to those above and below. Highly organised collagen structural
fibre bundles lie parallel to the dorsal surface within individual plies of the bone matrix as
well as perpendicular to the dorsal surface. We infer that the pelvic shield would have
proved effective as a tough, protective defensive structure. The histology of the pelvic shield
of this Isle of Wight ankylosaur is dissimilar to current Polacanthus descriptions and may be
unique to this taxon.
(South Dakota, USA)
Formation (South Dakota, USA) with the three most common crocodilian species being
Thoracosaurus neocesariensis, Borealosuchus sternbergii and Brachychampsa montana.
This study has identified crocodilian teeth from a large collection made from a new site in the
Hell Creek Formation. The aim of this study was to determine if there were any significant
differences in the geometry and morphology of teeth that might help diagnose species and
establish possible niche partitioning. Ninety-six isolated teeth were collected
from a single locality in Northwest South Dakota. The height, labial-lingual depth, proximaldistal
width, and curvatures (labial, lingual and curvature at the carina) were measured for
each tooth. Linear regressions and ternary diagrams were used to analyse size and curvature
measurements between taxa. The teeth from the new site were identified as Borealosuchus
sp., Thoracosaurus sp. and Brachychampsa sp. The results from this study suggest a
relationship between tooth proportion (height, depth and width) and species with regards to
Borealosuchus and Brachychampsa but not Thoracosaurus and there is no correlation
between curvature and species. However, the general skull and dental morphologies of these
taxa suggest different feeding habits and thus potential niche partitioning. Brachychampsa
had short, broad and flat teeth towards the posterior end of the dentary, capable of shell
crushing. The snout morphology of Thoracosaurus and Borealosuchus suggest
Thoracosaurus was piscivorous whereas Borealosuchus was carnivorous. Dietary resource
partitioning enabled the coexistence of these three species.
In 1942, Leriche described a large species of thresher shark from the Neogene of the USA. He figured two specimens which he named Alopecias (= Alopias) grandis. The holotype, was from the Miocene Calvert Formation of Nomini Cliffs, Virginia. The other was reworked from the Neogene of the Charleston area This species, although not particularly rare, is poorly known and has received little attention in the subsequent literature. An undescribed species, of similar size but with a serrated cutting edge, is present in slightly younger beds within the Calvert Formation of Calvert Cliffs, Maryland USA. Both species are present in the Early and Middle Miocene of Malta. The new serrated species has now been described and is currently in press.
The Oxford Clay Working Group (OCWG) was set up in 2011, in collaboration with the quarry owners, to collect, protect and document vertebrate fossils from this very important resource. Despite collecting some fine fossils (particularly teeth and isolated bones) efforts to secure articulated or disarticulated skeletons have been hampered, not only by modern quarrying techniques, but by reluctance of the operators to excavate to the most productive levels.
Here we report on a newly recovered, partially articulated plesiosaur skeleton representing a fully mature individual, which was saved because of the combined efforts of the OCWG in conjunction with both the quarry owners and employees.
The specimen, which has been safely conserved and secured by the group, will be deposited into an accredited institution and so made available for scientific study and, perhaps, public display. It is planned that the skull block is CT scanned which may not only provide hitherto unknown data relative to Plesiosauroidea but may help, together with other skeletal elements, to solve anatomical and taxonomic problems within Cryptoclididae and, perhaps, Elasmosauridae.
The collection contains approximately 90,000 specimens from all corners of the globe spanning from the Ordovician to the Pleistocene. Between 1836 to 1884 the Museum acquired thirty eight major collections containing fossil fish. Two of the most important fossil fish collections were purchased by the Museum in the 1880’s; William Willoughby Cole, the 3rd Earl of Enniskillen and Sir Philip de Malpas Grey Egerton. These collections comprised about 17,000 specimens.
In 1882 Arthur Smith Woodward joined the Museum and recognised the significance of the Fossil Fish Collection and almost immediately devoted all of his time and efforts into the study of fossil fish, culminating in the four part Catalogue of the Fossil Fishes in the British Museum (Natural History) published between 1989 and 1901. This is still used by many researchers today. Woodward went onto describe nearly 320 type specimens, the majority held in the NHM. Over the next 115 years the collections have continued to be added to and worked on. With many staff members undertaking expeditions to enhance the collections and developing techniques to expose fossils, such as Harry Toombs .
The collections are still heavily used by researchers from around the world today and we are still actively adding to the collection. Current curatorial projects involve digitising and making publically available the British Mesozoic holdings.
The 2015 fieldtrip in late February/early March was very eventful, with sudden snowfall and floods encountered, hidden mountainside quarries visited, little publicised dinosaur trackways discovered and fossil fakery by skilled preparators witnessed at first hand!.
This presentation highlights the scientific value and potential pitfalls of such collaborations.
Canada
all southern Alberta rivers, a new dinosaur tracksite was discovered. Investigation of the site
in the spring of 2015 resulted in the discovery of another, even better set of tracks and
trackways, and while working on these first two more sets of tracks were found. The blocks
of sandstone hosting the tracks are immense, and it was felt that cutting out the tracks was too
risky- both for safety of the people involved and the survival of the tracks. Instead, large latex
rubber peels, reinforced with an open weave cloth, were made of the tracks. The very hot
field conditions – full sun exposure all day with temperatures of 32-36C every day made for
challenging moulding conditions. The large peels were successfully returned to the museum
where a very thin layer of the very strong, fibre glass reinforced plaster will be used to make
a cast. The intention is to display these thin casts by hanging them on walls with low angle
lighting from the edge of the cast, along with a map illustrating the various.
fish Leedsichthys was excavated from the Star Pit, just outside Whittlesey, one of the
last clay brick pits that Alfred Leeds collected from. Consisting of over 2,300 parts, the
specimen became known as ‘Ariston’ because it went on and on, rather like the old utility
advertisement. It took over 3,100 staff hours to excavate this prodigious quantity of material,
achieving the record of the longest single dig for a vertebrate specimen in Europe.
In July 2015, the Esmée Fairbairn Foundation awarded a grant to Vivacity-Peterborough
Museum & Art Gallery through the Museums Association’s Collections Fund, to complete
the work on this specimen. The funds for the Leviathan Project will be used for the specimen
to be fully curated, with all associated field documentation including excavation maps, field
photographs, video dig diaries and specimen registration books. As well as being used for
school activities and events, photography will be employed to help create an online exhibition
and website, linking to other collections with stores of this animal’s remains around the
world. Staff development will occur to ensure the necessary understanding is in place
institutionally for long-term access and the global significance of the specimen. As a further
part of the legacy from this project, it will provide training for individuals to complete the
final stages of preparation, conservation and long-term storage of the final excavated
elements of the specimen, completing the work started by Alan Dawn in 2002.
It was from the start obvious that it contained parts of the Carapace and limb bones from a turtle. Once in the lab of Museernes Bevaringscenter I Skive, our “normal” procedure of preparing vertebrate fossils was used.
First Hammer and chisel, diamond rotating tools and heavy pneumatic tools was used, switching to finer tools when coming closer to the fossil surface, then, normally Acetic acid preparation buffered with Calcium orthophosphate would be used. This was changed when the first traces of a thin carbon layer was discovered. This layer represents preserved skin and is as thin as a pencil line and just as fragile, in itself acid resistant but when on top of soluble carbon carbonate concretion, disappears in a few moments when acid is applied. The skin is finely preserved on parts of the carapace, totally on one of the carapace horn plates and sensationally for this location between the toes of one of the hind legs.
The preparation was after this discovery mostly mechanical: scalpel, needles scrapers and pneumatic tools. When finished after a year we have half of the carapace, parts of the pelvis with complete Sacrum, the complete tail and both hind legs almost completely prepared so you see the preserved skin between the toes. It was also possible to collect parts of counter plate with skin impression during the preparation and this is presently being studied by Johan Lindgreen, University of Lund.
This specimen will undoubtedly add new understanding to the early Eocene Turtles.