Category: Dinosaur and Prehistoric Animal News Stories

On the Hunt for Troodon

Famous Canadian Palaeontologist Plans to Track Down Troodon

Professor Phil Currie (University of Alberta) is making plans for next summer, they include an expedition to hunt for a complete skeleton of the fast-running member of the dinosaur clade Deinonychosauria.  Phil Currie is hoping to hunt down Troodon.

Professor Phil Currie – Next Year Hunting for Troodon

Palaeontologist Phil Currie.

With “the best-preserved baby horned dinosaur ever found”, but will Phil Currie find a Troodon?

Picture Credit: Bruce Edwards (from a video interview)

Troodontids are a group of small Theropod dinosaurs that seem to fall somewhere in the phylogeny of the Dinosauria between the ornithomimids and the fearsome dromaeosaurids.  Troodon, may have been typical of this group, being fast-running, between two to three metres long (mostly tail), having a small skull with a long snout, large eyes and a big brain.  Relative to its body size, the species Troodon inequalis has the largest brain of any mature dinosaur yet described.  However, this genus is only known from a few specimens, and no complete skeleton of this dinosaur has ever been discovered.

An Illustration of a Troodontid (Troodon formosus)

Troodon illustrated.

An illustration of the feathered dinosaur Troodon.

Picture Credit: Everything Dinosaur

A Typical Member of the Troodon Family of Dinosaurs (Scale Drawing)

Troodontidae scale drawing.

A scale drawing of a typical member of the Troodontidae dinosaur family.

Picture Credit: Everything Dinosaur

Phil Currie, hopes to change all that and by doing so, help to assign with greater confidence, the various dinosaur genera associated with the Troodontidae family.  The family tree certainly needs some revision, after all the Troodon genus was originally set up on the basis of the description of a single fossil tooth (albeit a very distinctive tooth).  The famous Canadian palaeontologist, will lead a field team to the County of Grande Prairie (north-western Alberta, Canada) setting up a major dig in the Pipestone Creek area.  The rocks in this area were laid down in the Late Cretaceous and a number of bedding planes contain extensive bonebeds.  There have already been several important Theropod dinosaur discoveries made in this area, for example, earlier this year Everything Dinosaur published an article on the newly described, dog-sized, meat-eating dinosaur Boreonykus, which has been assigned to the Velociraptorinae sub-family of the Dromaeosaur family.

To read more about this new dinosaur discovery: Boreonykus certekorum A polar dinosaur related to Velociraptor

The teeth, which are relatively small, are easily identified thanks to their very large, hook-like serrations.  Isolated broken teeth are quite frequently found in the Grande Prairie area, but articulated bones and a fully intact skeleton are what the research team will be hoping to find.

Phil Currie explained:

“We find its teeth [Troodon] all the time up in the Grande Prairie region, yet in the rest of Alberta, it’s a pretty rare dinosaur.”

The Hunt for a Complete Troodon Fossil Specimen

Bones and teeth that have been assigned to the Troodontidae family have been found across North America and also in Asia, but despite the wealth of fossil material (mainly teeth), Professor Currie estimates that 90% of the bones in a Troodon skeleton remain unknown to science.

The Grande Prairie region could be just the spot to find the rest of the skeleton.  Many of the bedding planes where fossils are found represent low energy environments, which can aid the preservation of tiny bones such as those from a small, fast-running troodontid.  If lizards and mammals are preserved in these sediments then a three metre long, light and fragile Troodon might have been preserved too.

The Professor commented:

“It’s a big deal, because the more fragile skeletons tend to break apart, especially if there is a river nearby with a powerful current.  If you are an animal that’s falling apart because you’re rotten your big bones are not going to be washed very far by a river, but your small bones will be washed a long way.  Because small animals are being preserved there, we hope to find small dinosaurs as well.”

In the summer of 2017, a field team will descend on the Pipestone Creek bonebeds with the aim of identifying small fauna.  A team of Chinese palaeontologists, who have studied Asian troodontids are expected to join the researchers.

North-western Alberta in the Late Cretaceous – A Cretaceous Cross Roads

The northern part of Alberta has proved to be a happy hunting ground for vertebrate palaeontologists with a number of significant dinosaur discoveries having been made in the area.  The Upper Cretaceous rocks record important aspects of the region’s Late Cretaceous biota.  It seems that during this time in Earth’s history, North America was connected to Asia and a faunal interchange probably took place.  Several families of Asian dinosaurs have never been found in Canada, but Professor Currie is confident that one day, palaeontologists will uncover further evidence of this faunal interchange between the linked continents of Asia and North America.

Phil Currie, optimistically concluded:

“One of these days, I think we are going to find some, the potential is definitely there.”

Team members at Everything Dinosaur look forward to reporting on the research team’s progress.

Fossil Footprints Hint at Decline of Amphibians

The Rise of Reptiles as the World Dried Up

Places like the “Jurassic Coast” of Dorset, or the beaches that surround Whitby (North Yorkshire), might be synonymous with fossil hunting, but surprisingly, even some of our great cities can lay claim to be at the centre of palaeontological research.  Take the city of Birmingham (West Midlands), for example, not the sort of place that one would immediately associate with fossils (the exception being the amazing Wren’s Nest site to the north-west of Birmingham, Britain’s first national nature reserve for geology).  However, the study of a series of sandstone slabs, excavated from a quarry a few miles to the north of the centre of Birmingham is helping palaeontologists to plot global climate change some 310 million years ago, that led to the demise of amphibians and provided ideal conditions for the evolution and radiation of reptiles.

Birmingham, Like Most of the British Isles was once Covered in a Lush Tropical Carboniferous Rainforest

A carboniferous scene.

By the Carboniferous the insects were already highly diversified and the lush forests and swamps were dominated by Temnospondyls (primitive amphibians).

Picture Credit: Richard Bizley (Bizley Art) for more of Richard Bizley’s artwork visit: Bizley Art

In 1912, schoolteacher and amateur botanist Walter Henry Hardaker presented a paper to the Geological Society of London detailing the discovery of a series of Tetrapod footprints and trackways that he had discovered in a quarry located in the village of Hamstead.  Hamstead, itself has long since been swallowed up in the urbanisation of the area as the city of Birmingham expanded.  The quarry too, has gone covered up as houses, shops and offices were built, after all, the quarry was located just a stone’s throw from Hamstead railway station.

The sandstones became part of the Lapworth Museum of Geology’s fossil collection at the University of Birmingham.  Hardaker, an alumnus of Birmingham University, probably would have been fascinated by the recent research work undertaken by third-year Palaeobiology and Palaeoenvironments MSci student Luke Meade (University of Birmingham) and colleagues as they applied 21st Century analytical techniques to reveal a glimpse of the world when reptiles were beginning to take over from the amphibians as the dominant Tetrapods.

Using funding provided by the Palaeontological Association, the students scanned the twenty or so red sandstone slabs using state-of-the-art photogrammetric technology to provide a three-dimensional analysis of each track.  Colour coding of the images permitted the research team to produce topographic maps showing the individual contours of each specimen.  These three-dimensional images were then compared to other ichnofossils (trace fossils) to identify the types of animals which produced the footprints.

The footprints and tracks provide a remarkable insight into vertebrate life during the Pennsylvanian Epoch of the Late Carboniferous.  These trace fossils were formed as animals crawled over soft mud next to river channels.  A subsequent flood event covered these tracks with sand and helped to preserve snapshots in deep time.  The red sandstone slabs preserve amazing details, not only of the footprints and tracks but also raindrops and cracks in the mud that were formed as the area dried out.

To read an article on Carboniferous fossils from North Wales: Tropical North Wales 300 Million Years Ago

The research on these trace fossils indicates that the most common tracks were formed by amphibians, ranging from just a few centimetres in length (Batrachichnus salamandroides) to more than a metre long Limnopus ichnospecies).  Other types of creature traversed the mud, leaving their tracks, animals such as large Pelycosaurs (synapsids distantly related to modern mammals).  Although the tracks are much less common, their presence indicates that monitor lizard-sized Reptiliomorphs also roamed the swamps and low lying forest that was eventually to become the West Midlands of England.  The three-dimensional models of the footprints that the team were able to recreate, led to the identification of these tracks having been made by the ichnogenus Dimetropus.  Smaller reptilian tracks were identified as having been made by sauropsid reptiles, (Dromopus lacertoides), whose descendants gave rise to the crocodiles, marine reptiles, pterosaurs, dinosaurs and birds.

Limnopus Trace Fossils Used in the Study

Limnopus trace fossils (West Midlands).

Carboniferous footprints from the West Midlands (England) indicate the rise of amniotes.

Picture Credit: University of Birmingham/PeerJ

The photograph above shows a well-defined example of Limnopus isp tracks from the Hamstead quarry.  The top photograph shows a dorsal view of the fossil material, (B) tracks rendered to show relief with an arbitrary scale, whereas, (C) shows tracks rendered to highlight areas of steep gradient, digitally isolating the outline of the tracks to aid genus recognition and cross comparison.

Scale bar = 10 cm.

This ichnofauna associated with the Hamstead trace fossils contrasts with the slightly stratigraphically older, more extensive and better-studied assemblage from Alveley (Shropshire), which is dominated by small amphibians with relatively rare Reptiliomorphs and Dromopus tracks are absent. The presence of Dromopus lacertoides at Hamstead, identified from this new study supports the theory that the world was gradually becoming more arid through the Late Carboniferous and different types of reptile were beginning to flourish.

Batrachichnus salamandroides Tracks Preserved in the Red Sandstone of Hamstead Quarry

Batrachichnus fossil trackway.

Hamstead quarry red sandstone showing trace fossils of the Carboniferous amphibian Batrachichnus.

Picture Credit: University of Birmingham/PeerJ with additional annotation by Everything Dinosaur

In the picture above, tracks made by the amphibian Batrachichnus salamandroides are shown, the red line indicates the direction of travel, the long thin lines are tail drag marks.

As the world become drier, so those animals that did not have such a reliance on water compared to the amphibians would have had a distinct advantage.  The synapsids and the diapsids being amniotes (they lay eggs on land or retain a fertilised egg within the female), would have had a significant evolutionary advantage over the amphibians that relied on returning to water to reproduce.

The scientific paper: A Revision of Tetrapod Footprints from the Late Carboniferous of the West Midlands, UK (PeerJ).

Bird Melanosome Stories Flocking Together

Keratin and Melanosomes Preserved in Eoconfuciusornis

A team of international scientists led by researchers from the Chinese Academy of Sciences in collaboration with colleagues from North Carolina State University and Linyi University (Shandong, China), have reported finding the oldest fossil evidence of beta-keratin and melanosome preservation in the feathers of a 130 million-year-old primitive bird from the famous Early Cretaceous Jehol Biota of north-eastern China.

Writing in the journal “The Proceedings of the National Academy of Sciences (United States)”, this new study extends the time frame in which evidence of original organic molecules may be preserved and has provided new data on how to distinguish melanosome structures from similarly shaped microbes.  This is the second article related to the melanosomes having been identified in ancient birds that Everything Dinosaur has published the week.  The earlier article related to a bird fossil identified as a member of the Enantiornithes clade excavated from the Lower Cretaceous strata (Jiufotang Formation), that showed evidence of iridescence in its feathers.*  It’s almost as if stories relating to melanosome structures in birds are flocking together!

The Lower Cretaceous rocks exposed in the Chinese provinces of Hebei and Liaoning have provided palaeontologists with a huge number of vertebrate fossils to study.  The fine-grained strata, laid down in a lacustrine (lake environment), surrounding by active volcanoes provided ideal body fossil preservation conditions and many specimens have revealed exquisite details.  One of the most important group of fossils associated with these deposits are the many different types of bird fossil that have been found.   This new study was carried out on the fossilised remains of one such primitive bird, a specimen of Eoconfuciusornis.

Scanning transmission microscopy was undertaken to identify structures within the fossil and the surrounding matrix, chemical analysis including the use of antibodies that react to specific proteins, helped pinpoint the identity of the structures that had been found.

The Fossilised Remains of Eoconfuciusornis Used in the Research

Eoconfuciusornis fossil bird.

The fossilised remains of a Lower Cretaceous bird from China (Eoconfuciusornis).

Picture Credit: Dr Xiaoli Wang (Linyi University)

What Sort of Bird was Eoconfuciusornis?

Eoconfuciusornis was a crow-sized member of the primitive bird group the confuciusornithids that thrived in China during the Early Cretaceous.  It was one of the first birds to possess a pygostyle (the last five tail vertebrae fused together) and to have a keratinous beak lacking teeth, features found in all modern birds (Neornithes).

Previous studies had striven to prove that tiny, round or sausage-shaped structures preserved in association with fossilised remains were melanosomes, organelles found in animal cells that contains the light-absorbing pigment melanin responsible for colour and protection from harmful rays emitted from the sun.  However, although melanosome-like structures had been discovered in a number of specimens, there was an element of doubt as to the authenticity of the research findings.  It was difficult to definitively proved that these structures were not just microbes that had become associated with the feathers during decomposition and fossilisation.

Mary Schweitzer, a leader in the field of identifying traces of organic materials from within the fossil record and a co-author of this research paper explained the problem:

“If these small bodies are melanosomes, they should be embedded in a keratinous matrix, since feathers contain beta-keratin.  If we couldn’t find the keratin, then those structures could as easily be microbes, or a mix of microbes and melanosomes, in either case, predictions of dinosaur shading would not be accurate.”

The scientists used both scanning and transmission electron microscopy to map minute details of the feather’s surface and its internal structure.  They also utilised immunogold tagging, a technique which involves gold, non-reactive particles being attached to antibodies that bind to particular proteins in order to make them visible in electron microscopy.  This helped to show that the fine filaments within the feathers were keratin.

An Illustration of a Typical Confuciusornithid Bird of the Lower Cretaceous (Confuciusornis sanctus)

Confuciusornis sanctus.

Confuciusornis sanctus a primitive bird but it had a beak.

Picture Credit: University of Manchester

Further tests were carried out, including one which involved the mapping of the presence of copper and sulphur in association with the feathers when viewed under high resolution.  Sulphur was broadly distributed, reflecting its presence in both melanin molecules and keratin.  However, the distribution of copper (only found in modern melanosomes and not part of keratin), was only observed in the fossil melanosome structures.  The data produced supports the identity of melanosomes and indicates that these structures are not the result of contamination or microbial action.

Fellow author, Yanhong Pan (Chinese Academy of Sciences) stated:

“This study is the first to demonstrate evidence for both keratin and melanosomes, using structural, chemical and molecular methods.  These methods have the potential to help us understand, on the molecular level, how and why feathers evolved in these lineages.”

If melanosomes can be positively identified within the fossil record and as the shape of melanosomes can provide an indication of animal colouration, then palaeontologists may be able to hypothesise with greater confidence the colouration of extinct animals including dinosaurs and primitive birds.

* To read Everything Dinosaur’s recently published article on the study of a member of the Enantiornithes clade that shows evidence of iridescence in preserved feathers: A Prehistoric Bird with Bling

The scientific paper: “Molecular Evidence of Keratin and Melanosomes in Feathers of the Early Cretaceous Bird Eoconfuciusornis”, published in the Proceedings of the National Academy of Sciences (United States of America).

Ginkgo “Living Fossil” Has Remarkable Genome Sequenced

The Genome of the Ginkgo Reveals Secret of Success

A team of international scientists writing in the open-access journal “GigaScience”, have published a paper that maps the genome of a “living fossil” – the Ginkgo tree.  The extant Ginkgo (Ginkgo biloba), is the only representative of a division of the Plantae Kingdom called the Ginkgophyta.  Native to China, this slow-growing tree with its distinctive fan-shaped leaves has a fossil record that dates back to the Permian.  Also called the Maidenhair tree, Ginkgo biloba is the only living species of a once diverse and widespread group that thrived during the Mesozoic.  The evolutionary origins of the Ginkgophyta are unclear, with the huge genome of G. biloba mapped, it may be possible to trace the ancestry of this enigmatic plant.

The Genome of the “Living Fossil” Ginkgo Biloba has been Mapped

A Ginkgo biloba tree.

A small Ginkgo tree (G. biloba). The genome of Ginkgo biloba has been mapped.

Picture Credit: Everything Dinosaur

What is a Genome?

A genome is a complete set of genetic instructions required to build an organism, allow it to grow, develop and function properly.  The instructions are comprised of DNA (Deoxyribonucleic acid), which itself consists of four nucleotide bases adenine, thymine, cytosine and guanine (plus other materials that make up the DNA molecule such as phosphate and sugars).  The DNA is contained in chromosomes, which are found in the nucleus of most cells. The four nucleotides are arranged in pairs, adenine binds to thymine and cytosine unites with guanine.  The gene is the unit of inheritance, sections of the DNA consisting of an arrangement of the four base pairs make up a single gene and it is this gene that provides the instructions to build and maintain the organism.

Each organism has a unique genome and the length of these genetic instructions varies.  For example, the human genome is comprised of around 3.2 billion base pairs, if the genome of H. sapiens was printed out and put into paperback books, the stack of books would be over sixty metres tall, about as high as the monument to the Great Fire of London adjacent to London Bridge.  However, the Ginkgo has a much bigger genome, consisting of approximately 10.6 billion base pairs.  If the genome of G. biloba was printed into paperback form, the stack of books would reach over 200 metres high, that’s as tall as the giant cooling towers of the Fidlers Ferry Power station that dominates the Cheshire landscape.

The Human Genome Compared to the Much Larger Genome of Ginkgo biloba

Human genome compared to the Ginkgo genome.

If the human genome and the Ginkgo genome were printed as paperbacks, the tower of books representing the Ginkgo genome would be more than three times higher.

Picture Credit: Everything Dinosaur

In the picture above, the human genome if printed out into paperback books, would make a stack some 62 metres tall.  The much larger genome of G. biloba would make a tower of books over 200 metres high.  A Brachiosaurus is shown for scale.

The Extraordinary Biology of G. biloba

The research team, which included members of the Chinese Academy of Sciences and scientists from Zhejiang University, are trying to find out why individual trees can live so long and how they overcome insect and fungi attacks.  The Ginkgo genome mapping study is part of a much larger research project studying plant defences against pathogens.  This investigation will help palaeobotanists to better understand the evolutionary history of the Ginkgophyta and how they relate (phylogeny) to other plant groups.

Professor Yunpeng Zhao (Zhejiang University), one of the authors of the scientific paper commented:

“Ginkgo represents one of the five living groups of seed plants, and has no living relatives.  Such a genome fills a major phylogenetic gap of land plants, and provides key genetic resources to address evolutionary questions like phylogenetic relationships of gymnosperm lineages, evolution of genome and genes in land plants, innovation of developmental traits, evolution of sex as well as history of demography and distribution, resistance and conservation of the Ginkgo.”

Fossilised Ginkgo Leaves (Jurassic)

The carbonised fossil leaves of a Jurassic Ginkgo tree.

Ginkgo fossil leaves.

Picture Credit: Everything Dinosaur

A Very Resilient Plant

The resilience of the Ginkgo has fascinated botanists.  It has survived dramatic climate change including mini Ice Ages in its native China and Ginkgo trees in the Japanese city of Hiroshima were one of the few organisms to survive the atom bomb blast and resulting radiation, the oldest recorded individual tree germinated back in the Bronze Age.

Ginkgo trees are also able to fend off attacks from insects, bacteria and fungi.  The leaves contain an arsenal of complex chemicals that provide an effective defence.  To better understand the Ginkgo’s defensive systems, the authors analysed the repertoire of genes present in the genome that are known to play a role in the defence of the plant.  An initial analysis of the tree’s more than 40,000 predicted genes showed extensive expansion of gene families that provide for a wide range of defensive mechanisms.

Genes that enable resistance against pathogens are often duplicated.  In addition, Ginkgo trees have an extra weapon in their battle against Arthropods.  As well as having their own array of insecticides within their leaves, they also defend themselves against attack by releasing volatile organic compounds that specifically attract enemies of plant-eating insects.

The term “living fossil” is not one readily used by scientists.  It implies that a species has survived unchanged of millennia.  This is not true, the fossilised leaves preserved in Mesozoic and Cenozoic strata represent a wide variety of genera, but the tree’s basic body plan, its design has remained relatively unchanged for millions of years.

This new data, indicating that the Ginkgo has a formidable array of weaponry to keep it safe from harm, defence measures that seem to have come about as the genes were duplicated, might be linked to the plant’s remarkable resilience.  By undertaking a study of the Ginkgo and its genome, scientists may find useful pointers to assist them in helping to produce more robust crops that can resist diseases and pests.

The CollectA Ginkgo biloba Model

CollectA added a twenty-five centimetre high model of a Ginkgo tree into their “Prehistoric Life Collection” a couple of years ago.  This replica works well with the 1:20 scale range of prehistoric animal models and is very useful when creating realistic prehistoric scenes and dioramas.

The CollectA Prehistoric Life Ginkgo biloba Model

 CollectA Ginkgo biloba model.

The CollectA Ginkgo biloba tree model.

Picture Credit: Everything Dinosaur

To view the CollectA Ginkgo biloba replica and the other scale models in this range: CollectA Scale Models and Replicas

Just When Did the Dinosaurs Dominate the Land?

Ixalerpeton polesinensis and Buriolestes schultzi Co-existed

New fossil evidence suggests that the rise of the Dinosauria was more gradual than previously thought.  Many people’s perception of the dinosaurs is that they are all super-sized monsters, dominating life on land and rapidly out competing the other, more primitive Triassic reptiles.  Scientists writing in the journal “Current Biology” challenge this view, as they describe the discovery in the same rock formation of an early dinosaur and a lagerpetid, a member of a group of animals that are recognised as precursors of dinosaurs.  This is the first time that a dinosaur and a dinosaur precursor have been found together, indicating that true members of the Dinosauria Order and their near relatives co-existed.

The Skull of the Dinosaur (Buriolestes schultzi) in Situ

Buriolestes skull at the dig site.

The skull of the sauropodomorph Buriolestes.

Picture Credit: Cabreira et al

A Sauropodomorph and a Lagerpetid

 A team of researchers including Sergio Furtado Cabreira (Museu de Ciências Naturais, Universidade Luterana do Brasil, Brazil) and Alexander Wilhelm Armin Kellner (Departamento de Geologia e Paleontologia, Museu Nacional-UFRJ, Rio de Janeiro, Brazil) have described two new species of Dinosauromorpha from Upper Triassic rocks in central, eastern Brazil (the Paraná Basin).  The fossil material represents a lagerpetid, which has been named Ixalerpeton polesinensis and a new basal sauropodomorph (Buriolestes schultzi), the remains of these animals were found in the Alemoa Member of the Santa Maria Formation, specifically, within the Hyperodapedon (rhynchosaur) Assemblage Zone which dates from the Carnian faunal stage of the Upper Triassic.  Ixalerpeton has been assigned to the family Lagerpetidae which together with the Dinosauria and other closely related Archosaurs, make up the clade Dinosauromorpha.  B. schultzi has been assigned to the Sauropodomorpha, a clade of lizard-hipped dinosaurs that would evolve into the long-necked giants such as Diplodocus, Apatosaurus and Brachiosaurus.

Line Drawings and Photographs of the Fossilised Remains of the Two New Species of Dinosauromorph

Fossils and drawings of the two Dinosauromorpha.

Line drawing (A) of I. polesinensis and fossilised remains of (B-H) and line drawing (I) of B. schultzi with fossil remains (J-P).

Picture Credit: Current Biology

The lagerpetid (Ixalerpeton) has been described from skull bones including the braincase, vertebrae, one shoulder blade, the left humerus, parts of the pelvis, a thigh bone (femur) and some lower leg bones.  This biped is estimated to have measured around half a metre in length. The larger Buriolestes is estimated to have measured around 1.8 metres long and it has been described from a partial skull, which includes the premaxilla, maxilla and the dentary, a large number of vertebrae including posterior dorsal vertebrae and caudal bones, the left arm, parts of the pelvis and a nearly complete left hind leg.

Etymology

Ixalerpeton polesinensis – The genus name means “leaping reptile”, whilst the trivial name references São João do Polêsine, the town where the fossils were found.

Buriolestes schultzi – The genus name means “Buriol robber”, a reference to the family name of the land owners and recognises that this dinosaur was most likely carnivorous.  The species/trivial name honours Cesar Schultz (professor of vertebrate palaeontology at the Universidade Federal do Rio Grande do Sul).

A Timeline Showing the Relationship between B. schultzi and I. polesinensis within an Overview of Early Dinosauromorphs

A timeling showing the evolutionary relationships of early dinosauromorphs.

Phylogeny of early dinosauromorphs.

Picture Credit: Current Biology

The research team are confident that further analysis of the Ixalerpeton fossil material will add to our understanding as to how the dinosaurs evolved their anatomical characteristics.  The teeth of Buriolestes indicate that this sauropodomorph, a distant ancestor of the huge herbivorous Sauropods, was actually carnivorous.  This evidence supports the theory that the giant plant-eating dinosaurs such as Diplodocus were descended from small, bipedal, meat-eaters.

A Close View of the Teeth of Buriolestes Indicating that this Dinosaur was a Carnivore

The teeth of Buirolestes

A close view of the teeth of Buriolestes. The highly recurved and serrated teeth indicate that this sauropodomorph was a carnivore.

Picture Credit: Cabreira et al

The Dietary Preferences of Dinosauromorphs

An analysis of the fossil teeth of these newly described Archosaurs has helped scientists to assess the dietary preferences of a range of dinosauromorphs.  This research suggests that the very first dinosaurs were all meat-eaters and over time there was a move towards herbivory and an omnivorous diet within certain groups.

The Dietary Preferences of Dinosauromorphs

The diets of dinosauromorphs.

The dietary preferences of members of the Dinosauromorpha.

Picture Credit: Current Biology

The diagram above shows a cladogram of dinosauromorphs and photographs of their teeth.  The top photograph shows the teeth of the dilophosaurid Theropod Dracovenator (Neotheropoda), a carnivore.  Next comes a picture of the teeth of Buriolestes, assigned to the Sauropodomorpha but regarded as carnivorous by the researchers.  The third photograph features the teeth of Pampadromaeus, which coincidentally, was named by Sergio F. Cabreira, Cesar L. Schultz et al.  This little dinosaur has been assigned to the Sauropodomorpha too, it is also believed to be meat-eater.  The final set of teeth belong to the later sauropodomorph Plateosaurus, that lived some fifteen million years after Buriolestes and Pampadromaeus.  The teeth of Plateosaurus seem to be adapted to a plant-eating diet.

The hypothesis about feeding preferences advocated by the researchers in this paper is shown on the left of the cladogram, with alternative arrangements shown on the right.

Key

green coloured line = herbivory and/or omnivory

black coloured line = unknown or ambiguous

orange = carnivore (faunivory – feeding on other animals)

An Illustration of a Buriolestes Catching a Hyperodapedon whilst a Group of Ixalerpeton Scatter

A Buriolestes and Ixalerpeton illustrated.

A Buriolestes catches a Rhynchosaur whilst a group of Ixalerpeton hunt for lizards and grubs in the undergrowth.

Picture Credit: Oliveira Maurílio

This research lends weight to the hypothesis that dinosaurs evolved in the southern hemisphere and that the Dinosauria were carnivorous in their basal forms, it also supports the idea that lagerpetids and early dinosaurs were contemporaries since the first stages of dinosaur evolution.

The scientific paper: “A Unique Late Triassic Dinosauromorph Assemblage Reveals Dinosaur Ancestral Anatomy and Diet” published in Current Biology.

Prehistoric Bird with “Bling”

Study Suggests Early Cretaceous Bird Had Flashy Feathers

Fossils from the Jiufotang Formation of Liaoning Province (China), have provided scientists with an extensive data set that records life in the Early Cretaceous.  The highly fossiliferous strata (referred to as a Lagerstätte), has given palaeontologists a deep understanding of the fauna of a forested habitat with many large lakes.  Numerous fossils of turtles, pterosaurs, fish, mammals and dinosaurs have been described, but perhaps the Jehol Biota’s greatest contribution to our understanding of vertebrate evolution has come from the large numbers of bird fossils that have been found.  A team of international researchers have studied the ancient feathers of one such bird and deduced that it had sparkly, iridescent feathers probably for display in a bid to attract a mate.

Ancient Prehistoric Bird Provides Evidence of Iridescent Feathers

Ventral view and line drawing of the bohaiornithid bird specimen.

Ventral view of the new bohaiornithid specimen (CUGB P1202, primary slab). A, photograph of the primary slab. B, interpretive drawing.

Picture Credit: Jennifer A. Peteya (University of Akron)

A Bohaiornithid Bird with Bling

Scientists from Akron University (Ohio), the University of Texas at Austin in association with Chinese colleagues have studied the slab and counter slab of a beautifully preserved primitive bird.  Using high magnification and a non-destructive chemical technique to identify molecule signatures (Ramon spectroscopy), the team have identified melanosome structures that are associated with iridescent colouration in modern birds.

The image above shows a view of the primary slab showing the bird fossil (A), whereas (B) shows an interpretative line drawing of this enantiornithine.  The bird has been classified as a basal member of the Enantiornithes clade and the teeth in the tiny beak have led to the fossil being assigned to the Bohaiornithidae family (predatory birds).  As far as we at Everything Dinosaur are aware, no genus name has been assigned as yet.

The Rich and Diverse Early Cretaceous Forests of Northern China

The rich and diverse Daohugou Biota.

A rich and diverse environment dominated by small mammals, Pterosaurs, primitive birds and feathered Theropods.

Picture Credit: Julia Molnar

What are Melanosomes?

Using electron microscopes to look inside the feathers of the ancient bird, the research team were able to identify strange shapes and structures.  These are melanosomes, which when the animal was alive would have contained the pigment melanin.  This light-absorbing pigment is what gives colour to human hair and animal fur, as well as to the feathers of dinosaurs and birds.  The shape of the melanosome suggests the colour.  The crown, neck, and body contour feathers retain elongate melanosome structures associated with weakly iridescent colouration in living birds, so the team have concluded that this prehistoric bird was also iridescent.

Identifying Melanosomes in a Fossil Bird

Evidence of preserved melanosomes in Early Cretaceous bird.

The right wing and body contour feathers of the primitive bird (specimen CUGB P1202). Photographs B and C are highly magnified sections showing preserved melanosomes.

Picture Credit: Jennifer A. Peteya (University of Akron)

The photograph above shows part of the fossil from the primary slab (specimen number CUGB P1202).  Part (A) shows a close up of the right wing and the long contour feathers next to the tibia (lower leg bone).  The white triangle and white circle show the location of melanosome sampling sites.  Long, linear structures can be seen under high magnification in (B), the scientists have concluded that these are melanosomes, Photograph B is a highly magnified section or contour feathers near the tibia – the white triangle sampling spot.  Photograph (C) shows potential degraded melanosomes from the right wing sampling site – the white circle.  Scale bars represent 1 cm (A); 1 μm (B, C).

A Showy Sub-Adult Specimen

Colourful displays are commonplace in extant birds and many species use bright feathers for courtship display.  This specimen provides evidence of potential intraspecific communication using plumage in a member of the Bohaiornithidae.  Unfused bones in the skeleton indicate that this individual was a sub-adult, it seems these primitive birds did not hang about when it came to finding a mate.

Commenting on the significance of the study, lead researcher Dr Jennifer Peteya (University of Akron) stated:

“Many enantiornithine birds possessed ornate feathers.  This new specimen shows that some enantiornithines also had iridescent feathers and unlike most modern birds, these flashy ornaments developed before the animal was fully grown.”

The scientific paper: “The Plumage and Colouration of an Enantiornithine Bird from the Early Cretaceous of China”, published in the journal “Palaeontology”.

To read an article on the discovery of melanosome structures in a Chinese dinosaur fossil: Sinosauropteryx – A Ginger Dinosaur!

Dinosaur Claw Proteins Preserved for 75 Million Years

Researchers Get Their Claws into Citipati osmolskae

Researchers at North Carolina State University have published a paper in the Proceedings of the Royal Society B. (biology), that once again challenges the idea that organic material cannot survive the fossilisation process and persist in the fossil record for millions of years.  One of the authors of this study, Mary H. Schweitzer caused a sensation when in 2005 she claimed to have found T. rex soft tissue and proteins preserved in fossil bone.  Dr Schweitzer’s research has put her at the heart of a new area of palaeontology, the search for evidence of organic remains within the fossil record.  It is another Theropod that takes centre stage this time, a dinosaur called Citipati osmolskae.  Citipati was a member of the Oviraptoridae, a very bird-like family of Late Cretaceous dinosaurs.   A number of C. osmolskae specimens are known, including individuals found preserved along with nests of their own eggs.  One such beautifully preserved specimen, MPC-D 100/979, nick-named “Big Mamma” was studied using scanning and transmission electron microscopy to identify minute details of both the fossil’s surface and its internal structure in a bid to assess whether any organic material persisted in the fossilised claws.

The Citipati osmolskae Specimen Studied “Big Mamma”

Citipati osmolskae fossil.

The Citipati fossil sitting on a nest “Big Mamma”.

Picture Credit: M. Ellison/The American Museum of Natural History

The researchers have identified tell-tale signatures that suggest the preservation (on a microscopic level), of the original keratinous claw sheath that covered its digits.  This study adds to the growing body of evidence that original organic materials can be preserved over time.

The Oviraptorid Citipati osmolskae

Citipati osmolskae was a Theropod dinosaur that lived in what is now Mongolia during the Late Cretaceous.  In 1995, a particularly well-preserved specimen of Citipati was recovered from the Djadokhta Formation of Mongolia.  The specimen was found in a brooding position on a nest of eggs.  It is thought that the adult and nest were rapidly buried when a sand dune collapsed on top of them.  The nearly complete remains have been beautifully preserved and it had been noted that there was a thin lens of white material extending beyond one of the bony claws on a forelimb that differed in texture and colour from both the surrounding matrix and the bone.  It was also located where a claw sheath would be.   At around three metres in length (mostly tail), Citipati is one of the largest oviraptorids known, it is thought to be very closely related to Oviraptor.

An Illustration of a Typical Oviraptorid

A model of an Oviraptor.

A typical oviraptorid – Oviraptor philoceratops.

Picture Credit: Everything Dinosaur

Studying the Claws of “Big Mamma”

Alison Moyer, former PhD student at North Carolina State University, who is currently a postdoctoral researcher at Drexel University and lead author of a paper describing the research, wanted to find out if the material from Citipati was a claw sheath and if so, whether any original beta-keratin had preserved.  In extant Aves, (birds), claw sheaths cover the claw at the end of a digit much like fingernails in humans. The sheaths in modern birds are composed of two types of keratin, alpha-keratin, the softer form found on the interior of the sheath; and beta-keratin, a harder and more durable keratin that comprises the sheath’s exterior.  The team set out to discover whether they could detect the presence of beta-keratin.

Moyer and her university colleagues first used powerful scanning electron microscopy to assess the material.  The results showed that the sample was structurally similar to claw sheaths from modern birds, so the team decided to proceed with immunohistochemical (IHC) testing, this would identify the nature of the material preserved.

Highly Magnified Images Comparing the Internal Structure of Citipati Claw Sheath with the Internal Structure of an Ostrich Claw Sheath

Citipati dinosaur claw sheath studied.

TEM micrographs of (a) ostrich claw sheath and (b) Citipati claw sheath show similar structure.

Picture Credit: Alison Moyer

The images above are highly magnified micrographs of (a) ostrich claw sheath and (b) Citipati claw sheath which show a similar structure.  In both samples, parallel fibres can be seen running diagonally, and identical voids (yellow outlines) were observed among the fibres in both samples.

Immunohistochemical Testing (IHC)

IHC testing utilises antibodies that react against a particular protein.  If the protein is present, the antibodies bind to small regions of the protein and indicate where the protein is located in the tissue.  Moyer used beta-keratin antibodies derived from modern bird feathers.  In initial IHC testing, results were inconclusive, which led Moyer to look more closely at the specimen.  She found an unusually high concentration of calcium in the fossil claw, much higher than would be found in claws from the living birds used in comparison (such as Ostrich claw material), or from the sediment surrounding the fossil.  The team postulated that the calcium might be affecting results.  The calcium was eliminated and further IHC testing on the claw sheath material was conducted.  After the calcium was removed, the antibodies reacted much more strongly, indicating the presence of beta-keratin and preservation of original molecules.

Moyer explained:

“It’s probable the incorporation of calcium in the tissue helped preserve it, but that same calcium had to be removed in order to see the underlying molecular composition.  Because this study used multiple, well-tested methods, it not only supports the longevity of proteins in the rock record, it reveals a lot about how these might be preserved.”

The researchers conclude that calcium chelation greatly increased antibody reactivity, suggesting a role for calcium in the preservation of this type of fossil material.

The scientific paper: Microscopic and Immunohistochemical Analyses of the Claw of the Nesting Dinosaur, Citipati osmolskae, Proceedings of the Royal Society B.

Everything Dinosaur acknowledges the help of North Carolina State University in the compilation of this article.

Mineralised Blood Vessels in a Hadrosaur: Duck-billed Dinosaur Blood

Details of a Documentary about the work of Dr Schweitzer: The Search for Dinosaur DNA

Appreciating Dunkleosteus

Dunkleosteus Exhibit at the Naturmuseum Senckenberg

At the Naturmuseum Senckenberg (Frankfurt, Germany), visitors are treated to a spectacular gallery featuring that most diverse group of vertebrates, the fish.   Fans of Palaeozoic fossils can see several specimens on display, including a beautiful Dunkleosteus exhibit.

The Anterior Portion of Dunkleosteus on Display

Dunkleosteus on display.

The spectacular Dunkleosteus exhibit.

Picture Credit: Everything Dinosaur

Greeting you at the gallery entrance area is a cast of the plated skull and jaws of the giant Devonian predator Dunkleosteus.  It certainly is a most impressive sight.  Sharp-eyed readers can spot the John Sibbick illustration that can be seen behind the replica skull with its shear-like jaws.  In the background part of the fossil fish display can be seen.  It features a life-size model of a Coelacanth (Latimeria).

Standing Guard at the Fish Gallery Entrance – Dunkleosteus

A Dunkleosteus exhibit.

A Dunkleosteus cast on display.

Picture Credit: Everything Dinosaur

A Powerful Placoderm

Dunkleosteus was a huge, prehistoric fish with an armoured head made up of several bony plates that covered over thirty percent of the entire animal’s length. Larger specimens had dermal armour that was up to five centimetres thick.  The Placoderms (armoured fish); evolved in the Silurian period from ancestors that had no teeth, instead this group of fish developed a pair of extremely sharp bony plates that hung from the top jaw, the edges of the lower jaw were also bony and as sharp as a razor.  The jaws could be slammed together like a pair of self-sharpening shears.  Dr John Newberry formally named and scientifically described this apex predator in 1873.  The genus name honours the famous American palaeontologist Dr David Dunkle of the Cleveland Museum of Natural History.

As for size, a number of estimates have been published.  The Everything Dinosaur fact sheet sent out with Dunkleosteus model purchases suggests a maximum length of about nine to ten metres, with a maximum body mass of around four tonnes.

Apex Predator from Late Cretaceous Antarctica

Largest Mosasaur from Antarctica Described – Kaikaifilu hervei

A team of international researchers writing in the journal “Cretaceous Research”, have published details of the largest Mosasaur to be identified from Upper Cretaceous strata in Antarctica.  The newly described marine reptile has been named Kaikaifilu hervei, the scientists, which included Rodrigo Otero, a palaeontologist at the University of Chile and the lead researcher on the study, named the Mosasaur after “Kai-Kai filú,” an almighty giant reptile that ruled the sea in legends from the Mapuche culture from southern Chile and Argentina.  The species name honours Francisco Hervé (University of Chile), who has done much to improve our understanding of the palaeoclimate of Chile and Antarctica.

Kaikaifilu hervei fossil material was found by a Chilean palaeontology expedition to the remote Seymour Island (sometimes called Marambio Island), off the Antarctic peninsula.  This location has attracted a number of scientific expeditions in recent years as the strata exposed on parts of the island bridges the time period from the end of the Cretaceous and into the Palaeocene Epoch. The fossils, which include a fragmentary skull, plus a partial left humerus, elements from the jaw and about thirty teeth have been dated to around 66 million-years ago (López de Bertodano Formation).

The Estimated Size of Kaikaifilu hervei

Kaikaifilu hervei size comparison

Kaikaifilu hervei estimated to be around ten metres in length.

Picture Credit: Otero, R, A, Cretaceous Research with additional annotation by Everything Dinosaur

Based on better known Mosasaurs, the scientists estimate that K. hervei reached lengths in excess of ten metres.  It was probably an apex predator preying on the plesiosaurs that shared its shallow, marine environment.  The fossil skull is only the second Mosasaur skull known from Antarctica.  The other Mosasaur skull found in Antarctica represents the closely related, but earlier Taniwhasaurus antarcticus, which is estimated to have been about half the size of K. hervei.  T. antarcticus fossils have been found on James Ross Island, part of the same archipelago as Seymour Island.

The Fossil Excavation Site on Seymour Island

Mosasaur excavation site Seymour Island.

The desolate excavation site (K. hervei) Seymour Island in Antarctica.

Picture Credit: Otero, R, A, Cretaceous Research

Lead author of the study, Rodrigo Otero stated:

“Prior to this research, the known Mosasaur remains from Antarctica provided no evidence for the presence of very large predators like Kaikaifilu, in an environment where Plesiosaurs were especially abundant.  The new find compliments one expected ecological element of the Antarctic ecosystem during the latest Cretaceous.”

Kaikaifilu has been classified as a member of the Tylosaurinae sub-family of the Mosasauridae, as such, it was closely related to the Tylosaurus genus known from the United States.  The thirty or so teeth show heterogeneity (different shapes), this suggests that species of Mosasaur named from just their different shaped teeth may in fact represent the Kaikaifilu genus and the researchers have postulated that the discovery of heterogeneous teeth on Seymour Island may lead to some revision amongst the Mosasauridae.

The scientific paper: “Kaikaifilu hervei gen. et sp. nov., A New Large Mosasaur (Squamata, Mosasauridae) from the Upper Maastrichtian of Antarctica”

“Stuck in the Mud” Dinosaur Provides Insight into Oviraptorosaur Radiation

Tongtianlong limosus – One Very Unusual Fossil Posture

A team of international researchers, scientists from the Chinese Academy of Sciences, Dongyang Museum (Zhejiang Province, China) and Edinburgh University have announced the discovery of a new genus of bird-like dinosaur.  This newest member of the Oviraptoridae family, most likely met its demise when it became trapped in mud.  The animal was preserved with its forelimbs splayed out and outstretched as if beseeching someone or something to help pull it to safety. This dinosaur’s run of bad luck did not end in the Maastrichtian, the specimen was nearly blown up when construction workers were preparing the ground for the building of a new high school.

Two Views of the Fossil Skeleton Material (Tongtianlong limosus)

Tongtianlong fossils.

Two views of the holotype fossil material of Tongtianlong (a) dorsal view and (b) lateral view. Scale bar = 10 cm.

Picture Credit: Nature Scientific Reports (Junchang Lü et al)

Late Cretaceous Southern China was Oviraptorosaur Country

The fossil material, a near complete, three-dimensional specimen was saved by the construction workers, those who had narrowly avoided blasting the last resting place of this sheep-sized dinosaur to smithereens, a drill hole for an explosive charge can even be seen in the pelvic area of the holotype specimen (see photograph above).   The builders did their best to retrieve as much of the fossil material as they could.  With such an amazing skeleton to study, the researchers were quickly able to identify it is an oviraptorid and several unique characteristics led them to describe it as a new species.

An Illustration of Tongtianlong limosus Trapped in Mud

The feathered dinosaur Tongtianlong limosus mired in mud.

Tongtianlong trapped in mud.

Picture Credit: Zhao Chuang

This is the sixth species of oviraptorosaur* to have been discovered in the Upper Cretaceous strata (Nanxiong Formation), exposed in Ganzhou Province (south-eastern China).  The prevalence of oviraptorid fossil material may represent some form of preservation bias, but more likely, the fossil material indicates that this part of world was home to a variety of different types of oviraptorosaur.  Analysis of skull shape and the jaws suggest that each type of oviraptorosaur had evolved to exploit different food resources.  The number of different kinds of this type of dinosaur found in this locality suggests that oviraptorids were undergoing a radiation and rapidly evolving.  As such, these feathered, bird-like dinosaurs, may have been one of the last groups of dinosaur to undergo evolutionary radiation before their extinction.

The Skull of Tongtianlong limosus with Line Drawing  Below

Skull and line drawing of Tongtianlong limosus.

The skull of Tongtianlong with an accompanying line drawing.  Scale bar = 5 cm.

Picture Credit: Nature Scientific Reports (Junchang Lü et al)

Key

aof = antorbital fenestra, bc = braincase, d =dentary, emf = external mandibular fenestra, eo = exoccipital, f -= frontal, j = jugal, l = lacrimal, ltf = lower temporal fenestra, m = maxilla, n = nasal, nar = narial opening, npc = nasopharyngeal canal, o = orbit (eye socket see note), p = parietal, pm = premaxilla, pno = pneumatic opening, po = postorbital, q = quadrate, qj = quadratojugal, sq = squamosal and stf = supratemporal fenestra

Lots of Different Oviraptorid Dinosaurs in the Ecosystem

Tongtianlong is the sixth oviraptorosaurian taxon named from the Nanxiong Formation in this part of south-eastern China.  All these taxa have been named since 2010, the genera are:

  • Banji (B. long) named in 2010 – size unknown.
  • Ganzhousaurus (G.  nankangensis) named in 2013 – size not known.
  • Jiangxiasaurus (J. ganzhouensis) named in 2013 – size not known
  • Nankangia (N. jiangxiensis) named in 2013 – 2.5 metres long.
  • Huanansaurus (H. ganzhouensis) named in 2015 – 2.5 metres in length.

In the scientific paper the researchers explore the possible reasons why there were so many oviraptorids in Late Cretaceous southern China.  It could be due to “taxonomic inflation”, some of the specimens described could in fact be males or females of already known species or perhaps the fossils could represent already described species of dinosaur but different growth stages.  The scenario the scientists favour is that the fossils are documentary evidence supporting the idea that there was a genuine radiation of oviraptorosaurs.

The Scientific Paper: A Late Cretaceous Diversification of Asian Oviraptorid Dinosaurs: Evidence from a New Species Preserved in an Unusual Posture

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