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.

Keratin and Melanosomes Preserved in Eoconfuciusornis

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

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

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

Picture credit: Dr Xiaoli Wang (Linyi University)

For models and replicas of Chinese prehistoric animals including confuciusornithids: Dinosaur Models and Figures (PNSO).

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.

Studying Melanosomes

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 a primitive bird but it had a beak.

Picture credit: University of Manchester

Mapping Chemical Elements

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).

The Everything Dinosaur website: Everything Dinosaur.

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.

Early Cretaceous Bird with Bling

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 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

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

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!

For models and replicas of prehistoric animals such as Sinosauropteryx and enantiornithine birds: Age of Dinosaur Models from PNSO.

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.

Identifying Proteins in Dinosaur Fossils

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”

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.

A Model of Citipati osmolskae (Safari Ltd)

Citipati dinosaur model.

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.

For models and replicas of oviraptorids including Citipati (whist stocks last): Safari Ltd. Dinosaurs and Prehistoric Animal Figures.

An Illustration of a Typical Oviraptorid

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

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.

Dinosaur Claw Proteins

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.

Visit the website of Everything Dinosaur: Everything Dinosaur.

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.

Kaikaifilu hervei

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 estimated to be around ten metres in length.

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

An Apex Predator

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

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

Picture credit: Otero, R, A, Cretaceous Research

For models and replicas of plesiosaurs and mosasaurs: Papo Dinosaur and Prehistoric Animal Figures.

A Hunter of Plesiosaurs

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”.

The website of Everything Dinosaur: Everything Dinosaur.

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 dinosaur has been named Tongtianlong limosus.

Tongtianlong limosus

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)

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

Tongtianlong trapped in mud.

Picture credit: Zhao Chuang

A Sixth Species of Oviraptorosaur

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

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.

For models and replicas of Asian oviraptorid dinosaurs and other prehistoric animals: Age of Dinosaurs Figures from PNSO.

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”.

Visit Everything Dinosaur’s website: Everything Dinosaur.

Fossilised Dinosaur Brain Tissue Identified for the First Time

Bexhill-on-Sea may not be synonymous with ground-breaking palaeontology, but a visit to the local museum will reveal that dinosaur bones and teeth have been found in this part of East Sussex (southern England).  However, a small fossil measuring a little over ten centimetres long and five centimetres across, a fossil found on the foreshore area of the beach by amateur fossil collector Jamie Hiscocks in 2004, has proved to be the first fossilised dinosaur brain known to science.

A View of the Fossil – Preserved Parts of the Exterior of a Dinosaur’s Brain

A small pebble from the foreshore at Bexhill-on-Sea is actually part of the fossilised brain of a dinosaur.

Picture credit: Jamie Hiscocks/Press Association

The Brain from an Iguanodontid

Although the genus cannot be identified, the researchers which include Dr David Norman and Dr Alex Liu (Cambridge University), are confident that this 133-million-year-old (Lower Cretaceous) fossil, came from a large ornithopod, an iguanodontid.  Fossils of these herbivorous dinosaurs are known from the strata that is exposed in this area and the brain displays distinct similarities to modern-day archosaurs, the closest living relatives to the Dinosauria, crocodiles and birds.

For models and replicas of iguanodontids and other dinosaurs: CollectA Age of Dinosaurs Popular Figures and Models.

The Fossil Placed in the Correct Anatomical Position Within the Skull of an Iguanodontid

The location of the fossil within the skull of the iguanodontid.

Picture credit: Oxford University and Cambridge University

Meningeal Blood Vessels Identified

Scanning microscopy undertaken by colleagues at the University of Western Australia and three-dimensional animations provided by the University of Manchester reveal the meninges, the tough tissues surrounding the actual brain, as well as tiny capillaries and portions of the adjacent soft tissues representing the cortex.  The researchers describe these details as “mineralised ghosts”.

An Image from the Three-Dimensional Animation Provided by the University of Manchester

A still from the Manchester University animation which shows the fine detail on the fossil’s exterior.

Picture credit: University of Cambridge/University of Manchester

This remarkable research, a first for palaeontologists who specialise in studying the Dinosauria, has been published in a Special Publication of the Geological Society of London.  The paper has been published in tribute to Professor Martin Brasier (Oxford University), who sadly died in 2014 following a road traffic accident.  Professor Brasier had coordinated the research alongside Dr David Norman.  One of the co-authors of the paper Dr Alex Liu was a PhD student of Professor Brasier at the time the research project was started.

Dr Liu, explained the importance of this study:

“The chances of preserving brain tissue are incredibly small, so the discovery of this specimen is astonishing.”

A Dead Dinosaur with its Head Stuck Upside Down in Stagnant Water

According to the researchers, the reason this particular piece of brain tissue has been so well-preserved is that the dinosaur’s brain was essentially ‘pickled’ in a highly acidic and low-oxygen body of water.  Shortly after this dinosaur died, the corpse ended up in a shallow, stagnant pool, perhaps a bog or part of a swamp.  The skull ended up buried in the fine sediment at the bottom and this allowed the soft tissue structures to be mineralised before they began to decay.  This permitted the high degree of detail to be preserved.

A Magnified View of the Exterior of the Specimen

A close view of the fine structures preserved on the fossil material.

Picture credit: Oxford University and Cambridge University

Dr Norman commented:

“What we think happened is that this particular dinosaur died in or near a body of water, and its head ended up partially buried in the sediment at the bottom.  Since the water had little oxygen and was very acidic, the soft tissues of the brain were likely preserved and cast before the rest of its body was buried in the sediment.”

In collaboration with researchers from the University of Western Australia, the scientists employed scanning electron microscopy in order to identify the tough membranes, or meninges, that surrounded the brain itself, as well as strands of collagen and blood vessels.

A Highly Magnified Portion of the Brain Showing the Meningeal Blood Vessels

Tubular structures identified on the exterior of the brain interpreted as representing meningeal blood vessels.

Picture credit:  Oxford University and Cambridge University

Bird Brains and the Brains of Crocodilians

Such is the exceptional preservation of the specimen that the scientists have been able to identify mineralised structures that represent tissues from the cortex (the outer layer of neural tissue of the brain), along with delicate, tiny capillaries.  These preserved tissues, especially the meninges are homologous to the brain tissues of extant Aves and crocodiles, close relatives of dinosaurs.

Scanning Electron Microscopy Reveals Remarkable Details

The scanning electron microscope images revealed details of the internal structure of the outermost surface of the brain.

Picture credit:  Oxford University and Cambridge University

The picture above shows a highly magnified section of the fossil, sinuses as well as the tough and fibrous tissues protecting the actual brain can be made out.  Could “Dm” represent the Dura mater, the tough membrane that helps to protect the brain?

A Typical Reptilian Brain

Reptile brains (and bird brains for that matter), are shaped very differently from our own brain with its substantial cerebellum.  In most reptile brains, the brain is sausage-shaped, surrounded by a dense region of blood vessels and thin-walled vascular chambers (sinuses), the provide a blood drainage system.  The reptile brain only occupies about fifty percent of the actual cranial cavity.

In contrast, the tissue in the fossilised brain appears to have been pressed directly against the skull, raising the possibility that some dinosaurs had large brains, with a greater volume which filled much more of the cranial cavity.  With this one specimen to study, the researchers urge caution against drawing too many conclusions as to the intelligence of dinosaurs.  It is likely that post-mortem, the brain got pressed against the bony roof of the cranial cavity.  It is difficult to infer brain size based on the data available.

Not Sure How Big the Brain Was

Dr Norman added:

“As we can’t see the lobes of the brain itself, we can’t say for sure how big this dinosaur’s brain was.  Of course, it’s entirely possible that dinosaurs had bigger brains than we give them credit for, but we can’t tell from this specimen alone. What’s truly remarkable is that conditions were just right in order to allow preservation of the brain tissue, hopefully this is the first of many such discoveries.”

A Dinosaur Brain

Fossil hunter Jamie Hiscocks, the finder of the specimen back in 2004 said:

“I have always believed I had something special.  I noticed there was something odd about the preservation, and soft tissue preservation did go through my mind.  Martin realised its potential significance right at the beginning, but it wasn’t until years later that its true significance came to be realised.”

Everything Dinosaur acknowledges the help of Cambridge University in the compilation of this article.

The scientific paper:

Martin D. Brasier et al.’ “Remarkable Preservation of Brain Tissues in an Early Cretaceous Iguanodontian Dinosaur.” Earth System Evolution and Early Life: A Celebration of the Work of Martin Brasier. Geological Society, London, Special Publications.

Visit Everything Dinosaur’s website: Everything Dinosaur.