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/Dinosaur and Prehistoric Animal News Stories

Fossil finds, new dinosaur discoveries, news and views from the world of palaeontology and other Earth sciences.

3 10, 2017

Squid the Last Meal of a Baby Ichthyosaurus

By | October 3rd, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|1 Comment

Baby Ichthyosaurus communis Dined on Squid

A team of UK-based scientists have identified the youngest and therefore the smallest specimen of Ichthyosaurus communis known to science and, just for good measure, they have found what could have been the marine reptile’s last meal.  Inside the body cavity of the seventy-centimetre-long fossil, the researchers found tiny “hook-like” structures, these are the less digestible parts of squid and therefore, the scientists were able to deduce that this young Ichthyosaurus had recently fed on cephalopods.

A Young Ichthyosaurus communis Attacking a Prehistoric Squid

A neonate Ichthyosaurus communis feeding on a squid.

A neonate Ichthyosaurus attacks a squid.

Picture Credit: Julian Kiely

The artist Julien Kiely has kindly reconstructed the new-born in this fantastic scene, which depicts the moment a newly born Ichthyosaurus communis attacks a squid.

Commenting on the significance of this discovery, one of the authors of the scientific paper, published today in the journal “Historical Biology – The International Journal of Paleobiology”, Dean Lomax stated:

“It is amazing to think we know what a creature that is nearly 200 million years old ate for its last meal.  We found many tiny hook-like structures preserved between the ribs.  These are from the arms of prehistoric squid.  So, we know this animal’s last meal before it died was squid.”

From the Biggest to the Smallest

University of Manchester palaeontologist Dean Lomax, in collaboration with German colleagues, had recently published a paper describing the largest specimen of Ichthyosaurus communis, a female that turned out to be pregnant when she died.  Everything Dinosaur wrote an article about the research in August*, as well as having described the biggest I. communis, just a few weeks later, this new paper, describes the smallest.

Palaeontologist Dean Lomax Holds the Neonate Ichthyosaurus communis Specimen

Dean Lomax holding the neonate Ichthyosaurus fossil.

Palaeontologist Dean Lomax holding the baby Ichthyosaurus fossil.

Picture Credit: University of Manchester/University of Birmingham

*To read the article about the largest Ichthyosaurus communis specimen: Palaeontologists and the Pregnant Ichthyosaurus

Ichthyosaurus communis

Several species of Ichthyosaurus have been identified, but Ichthyosaurus communis was the first, being named and described in 1822 from fossil material discovered by Mary Anning.  These reptiles were viviparous and a number of specimens showing embryos preserved inside their mothers are known.  However, this Ichthyosaurus is one of only a handful of fossils that represent very young animals.  As it was not preserved in association with a larger specimen (the mother) and as there are stomach contents present, it is likely that this fossil represents an independent, recently born animal, the first neonate Ichthyosaurus communis skeleton to be described.

The Ichthyosaurus Fossil on Display at the Lapworth Museum of Geology, University of Birmingham

The neonate Ichthyosaurus communis fossil specimen.

The neonate I. communis specimen.

Picture Credit: University of Manchester/University of Birmingham

The fossil is definitely a new born and not a dwarf species of Ichthyosaur as the scientists noted the large ring of sclerotic bone relative to the eye socket and the poorly ossified (highly cancellous) bones of the skull and other parts of the skeleton, these signs all indicate that these are the fossilised remains of a very young marine reptile.

Niche Partitioning in the Ichthyosauria

The new specimen is from the collections of the Lapworth Museum of Geology, (University of Birmingham).  Palaeontologist Nigel Larkin, a research associate at Cambridge University, cleaned and studied the specimen in 2016,  as he prepared the fossil, he became aware of its potential significance.  Nigel has recently been involved in an extensive restoration project at Biddulph Grange in Staffordshire.  He has been helping to restore the Victorian Geological Gallery at this National Trust property to its former glory.  As one of the most highly respected fossil preparators in the UK, Nigel was able to reveal the fossil’s secrets as he cleaned and helped to preserve the delicate marine reptile skeleton.

To read an article about the Geological Gallery preservation project at Biddulph Grange: Fossil Hunting at Biddulph Grange

The discovery of squid remnants in the gut area suggests these types of Ichthyosaur specialised in hunting cephalopods.  Commenting on the implications of this fossil, Dean Lomax explained:

“This is interesting because a study by other researchers on a different type of Ichthyosaur, called Stenopterygius, which is from a geologically younger age, found that the small – and therefore young – examples of that species fed exclusively on fish.  This shows a difference in prey-preference in new-born Ichthyosaurs.” 

This could hint at niche partitioning, whereby similar species use different resources within an environment to reduce direct competition and to help them co-exist.

Dean Lomax and Nigel Larkin in Front of the Jurassic Seas Exhibit (Lapworth Museum of Geology)

The neonate Ichthyosaurus fossil on display.

Dean Lomax (left) and Nigel Larkin (right) in front of the Lapworth Geological Museum exhibit.

Picture Credit: University of Manchester/University of Birmingham

How Old is the Fossil?

The specimen, part of the vertebrate fossil collection of the Lapworth Museum of Geology, (University of Birmingham), has no provenance data associated with it.  Unfortunately, there were no collection notes or other details to help the palaeontologists to identify where the fossil came from.  However, permission was granted for Nigel to remove a small portion of the matrix surrounding the fossil.  He passed this on to Ian Boomer (University of Birmingham) and Philip Copestake (Merlin Energy, Resources Ltd), so that they could analyse the rock for microscopic fossils.  Based on the types of microfossil preserved, the scientists were able to identify that this Ichthyosaur was around 199-196 million years old, (uppermost Hettangian faunal stage to lowermost Sinemurian of the Early Jurassic).

Nigel outlined the difficulties the team faced:

“Many historic Ichthyosaur specimens in museums lack any geographic or geological details and are therefore undated.  This process of looking for microfossils in their host rock might be the key to unlocking the mystery of many specimens.  Thus, this will provide researchers with lots of new information that otherwise is lost.  Of course, this requires some extensive research, but it is worth the effort.”

In addition, establishing a microfossil signature for a fossil may also help in those cases where theft of fossil material is suspected.

As part of the study, the skeleton was Micro CT-scanned and a three-dimensional digital model was created by Steve Dey of ThinkSee3D Ltd.  Using medical imaging software, Steve converted the three sets of CT cross-sectional images (from scans of the tail, middle section and head) into a single digital three-dimensional model of the whole animal.  This non-destructive technique provided further key information helping to identify the species and potentially, helping to provide new data on Ichthyosaur ontogeny.

The beautiful new-born Ichthyosaurus is on display in the recently refurbished Lapworth Museum of Geology, University of Birmingham, which was nominated for the 2017 Art Fund Museum of the Year.

The scientific paper: “The First Known Neonate Ichthyosaurus communis Skeleton: A Rediscovered Specimen from the Lower Jurassic, UK” by Lomax, D. R., Larkin, N. R., Boomer, S., Dey, S. and Copestake, published in “Historical Biology”.

1 10, 2017

Pterosaur Study Sheds New Light on Jidapterus

By | October 1st, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Jidapterus edentus Gets Grounded

A team of researchers, writing in the on-line, academic, open access journal PLOS One, have published a reassessment of the Early Cretaceous Pterosaur Jidapterus (J. edentus).  This flying reptile, with a wingspan estimated to be between 1.6 and 1.7 metres, is one of a number of flying reptiles known from the Lower Cretaceous deposits of the Jiufotang and Yixian Formations, which between them have helped palaeontologists to build up a detailed picture about life in northern China some 125 million years ago (Jehol Biota).  In this new study, Jidapterus is identified as a valid genus (there had been some doubts raised over whether or not the single fossil specimen known represented another closely related Pterosaur species – Chaoyangopterus zhangi).  In addition, the authors postulate that Jidapterus might have been a ground dwelling forager, Everything Dinosaur team members have speculated that Jidapterus only took to the trees to evade predators or perhaps to roost.

The Only Known Specimen of Jidapterus edentus with an Accompanying Line Drawing

Line drawing and holotype of Jidapterus edentus.

The holotype fossil of Jidapterus edentus and accompanying line drawing.

Picture Credit: PLOS One

Tricky Pterosaur

Named in 2003, Jidapterus is known from a single, partially articulated and nearly complete specimen (holotype RCPS-030366CY).  It is a member of an enigmatic family of Pterosaurs called the Chaoyangopteridae (pronounced Chow-yang-op-tery-rid-aye).  Several species have been named, from Brazil (Lacusovagus) and from Lebanon (Microtuban), to read more about the Lebanese Pterosaur, the first flying reptile to be described from this part of the world: Pterosaur Fossil Flies Home.  Most of what palaeontologists know, about this family of flying reptiles, distantly related to the giant azhdarchid Pterosaurs, comes from studying the fossilised remains of chaoyangopterids from northern China.  Trouble is, these delicate flying reptile specimens associated with Liaoning Province are squashed as flat as a pancake.  The researchers identify a number of anatomical traits (autapomorphies) that reinforce the idea that Jidapterus should be considered as a distinct genus.

In addition, the scientists examined the feet and claws of Jidapterus and concluded that this flying reptile, once thought to have been a piscivore, was probably omnivorous, foraging on the forest floor for seeds and other plant material, as well as snatching up invertebrates and small creatures.  Whether or not the narrow, pointed beak (labelled in the diagram above) was entirely toothless remains open to debate.

The scientific paper: “The Toothless Pterosaur Jidapterus edentus (Pterodactyloidea: Azhdarchoidea) from the Early Cretaceous Jehol Biota and its Paleoecological Implications” by Wen-Hao Wu, Chang-Fu Zhou and Brian Andres published in PLOS One.

30 09, 2017

Strong-armed Sabre-Tooth Kittens

By | September 30th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|2 Comments

Sabre-Toothed Kittens and Their Strong Arms

A new study undertaken by scientists from California State Polytechnic University, the University of Wisconsin and colleagues at Bristol University, has concluded that Smilodon (S. fatalis), kittens were born with strong arms, stronger than similarly-sized modern big cats.  However, their pattern of bone development was congruent to other members of the Felidae.

Strong Kittens Grew up to be Strong Cats

Sabre-Toothed Cats

The famous “Sabre-Toothed Cat” – Smilodon.  Strong kittens – strong cats.

Picture Credit: BBC

The Treasure Trove of Fossils at La Brea

Using the extensive Smilodon fossil record preserved at the La Brea Tar Pits (Los Angeles, California), the researchers measured the limb bones of these big cats.  Only unbroken limb bones were included in the growth analysis.  Fortunately, given the huge number of Smilodon fossil specimens associated with this natural predator trap, the researchers, which included Donald Prothero, the author of “The Princeton Field Guide to Prehistoric Mammals”, that Everything Dinosaur was invited to review earlier this year* had a substantial data set to study.  For example, the scientists included thirty, Smilodon upper arm bones (humeri) representing cats at various growth stages in this study.  Their ontogenic analysis revealed that young animals had thicker and more robust bones than other members of the cat family (Felidae).  The bones did not become more robust as the cats grew, it seems Sabre-Tooths were born with big, strong arms.

Comparing the Upper Arm Bones of Big Cats Extant and Extinct 

Sabre-Toothed Cats were born with strong arms.

Comparing the humeri of extinct and extant big cats.

Picture Credit: PLOS One/DRP

The photograph shows a comparison of five big cat upper arm bones (the humerus).   The bones come from adult animals and provide a visual guide to the forelimb size of large felids.

From the left – the first, whitish bone is the humerus of a Mountain Lion (Cougar) – Puma concolor.  The second, whitish bone is the humerus from a Tiger, Panthera tigris.  The Tiger is a much bigger and heavier than the Mountain Lion.  The bone in the middle is the humerus of Smilodon fatalis, it is much thicker and more substantial.  The third whitish bone comes from a Lion Panthera leo.  The dark bone on the far right, comes from an extinct species that was contemporaneous with Smilodon.  This is the humerus of an American Cave Lion (Panthera atrox), the P. atrox bones used in the study also came from La Brea Tar Pits.

How Did the Limb Bones of Smilodon fatalis Change as the Cats Aged?

The research team discovered that whilst the arm bones of Smilodon, were more robust than those or extant big cats, they did not become more robust as the cats got older.  Smilodon kittens had big limb bones to begin with.  Mapping the bone growth (ontogeny), using the many specimens representing animals of different ages from the La Brea fossil collection, the team found that Smilodon grew in a similar way to other, primitive members of the Felidae and in the same way that many living cat species do today.  The bones lengthen and become more slender before they thicken.  This study, published in the on-line, open access journal PLOS One suggests that Felidae growth and development is much more constrained than previously thought, even in genera with very different morphotypes and bone structures.

Comparing the Radii of Big Cats (Living and Extinct)

Smilodon Limb Growth Study.

Comparing the radius of extinct and extant cat species.

Picture Credit: PLOS One/DRP

The photograph (above) shows the radii of the five species of big cat, laid out in the same order as the photograph which showed the humeri.  The radius is one of a pair of bones found in the forearm, it is the bone that is lateral to the body (facing the outside).

Left to Right:

  • Mountain Lion (Puma concolor)
  • Tiger (Panthera tigris)
  • Sabre-Toothed Cat (Smilodon fatalis)
  • African Lion (Panthera leo)
  • American Cave Lion (Panthera atrox)

Professor Prothero stated:

“Sabre-Tooth cats have extraordinarily strong front limbs for tackling and subduing prey before they slashed their throats or bellies with their sabre-like canine teeth.  Using the extraordinary collection of limb bones of Sabre-tooth kittens at La Brea, we found that their limbs don’t become more robust as they grew up, but instead retain the stereotypical growth pattern where the limbs grow longer more quickly than they grow thick.  To compensate, Sabre-tooth kittens were born with unusually robust limbs and retained that pattern as they grew.”

The limb measurements demonstrated that Smilodon fatalis kittens had the same growth curve graph as those of Tiger or Mountain Lion kittens, but they tended to be thicker from the outset.  For the same length of bone, the Sabre-Tooth kitten forelimb element (radius or humerus) always had a larger circumference than a comparably sized Mountain Lion or Tiger.

A Comparative Analysis of the Tibia of Smilodon (S. fatalis) Different Growth Stages

Smilodon tibia comparison.

Comparing the size of Smilodon leg bones (tibia).

Picture Credit: PLOS One/DRP

* Everything Dinosaur’s review of “The Princeton Field Guide to Prehistoric Mammals” by Donald R. Prothero: Field Guide to Prehistoric Mammals – Book Review

The scientific paper: “Did saber-tooth kittens grow up musclebound?  A study of postnatal limb bone allometry in felids from the Pleistocene of Rancho La Brea” by Katherine Long, Donald Prothero , Meena Madan, Valerie J. P. Syverson published in PLOS One.

28 09, 2017

New Basal European Ornithopod Described

By | September 28th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Burianosaurus augustai  – Unappreciated Ornithopods

If you were able to book yourself onto a time-travelling safari to the Cretaceous, before journeying into the long distant past, you might explain to the travel guide that you would be hoping to spot a Tyrannosaur, get up close to a browsing armoured dinosaur or possibly take some photos of Triceratops.  However, we suspect, that even if such a venture was possible, few tourists would spare a thought for one group of dinosaurs, that ironically, you would be much more likely to encounter.  These are the Ornithopods, that diverse and extremely successful group of bird-hipped dinosaurs, that are often overlooked.  A new basal Ornithopod has been named and described this week – Burianosaurus augustai.  A plant-eating dinosaur named after the palaeoartist Zdeněk Burian, who, in his lifetime did much to raise the profile of the Dinosauria.

An Illustration of Burianosaurus (B. augustai)

Burianosaurus augustai illustrated.

An illustration of the basal Ornithopod from the Czech Republic – Burianosaurus augustai.

Picture Credit: Edyta Felcyn

The Dinosaur Equivalent of Antelopes

They lacked horns, body armour and for the majority, they did not reach huge sizes, but these herbivores would have made up a significant component of the dinosaur fauna in most Cretaceous ecosystems.  If you were to go on a safari to the Maasai Mara of Kenya or the Serengeti of Tanzania, tourists might be keen to spot lions, leopards and elephants but in all likelihood, you would encounter a great many different types of antelope.   Dinosaurs like the newly described Burianosaurus can be considered as being the dinosaur equivalent of today’s antelopes.

Described from a single, well-preserved, left femur (thigh bone), Burianosaurus is the first dinosaur to be named from fossils found in the Czech Republic.  It is not the first dinosaur fossil from the Czech Republic to be scientifically described, that honour goes to a single, broken tooth from an indeterminate Theropod from Upper Jurassic sediments that was described in 2014, coincidentally by the lead author of the paper describing Burianosaurus, Daniel Madzia (Polish Academy of Sciences).

The Fossilised Thigh Bone of Burianosaurus (Various Views)

Specimen number NBP oB 203 (Burianosaurus left femur)

Views of the left femur, the only fossil from which the basal Ornithopod Burianosaurus augustai has been described.

Picture Credit: The Journal of Systematic Palaeontology

The photograph (above), shows various views of the left femur of Burianosaurus.  This is the holotype fossil (NMP Ob 203), from which this genus was described.  It is not common these days, to have a new dinosaur genus erected on the description of a single bone.  When this fossil was first studied back in 2005, it was assigned to the iguanodontids.  However, over recent years the Iguanodontia and their relatives have been subject to phylogenetic reassessment and many of the taxonomic relationships between different components of the Ornithopoda have been revised.  The single bone was preserved in such fantastic condition, that its shape and muscle scars proved crucial in assigning a new dinosaur genus.

The views of the femur are (A) a view from the front, (B) viewed from the back, (C) a medial view (the bone viewed from the side closest to the body, think of it as the “inside leg view”) and (D) a lateral view, the bone viewed from the side of the bone towards the outside of the body.  Photographs (E) and (F) are views of the bone from the top looking down (proximal) and from the bottom of the bone looking up (distal).

The scale bar is 10 centimetres and the white arrow in (A) indicates the site from which a small sample of fossil bone was taken to permit an internal examination of bone structure to take place.  This histology helped the research team, writing in the Journal of Systematic Palaeontology, to identify this specimen as coming from a young, adult animal.

Bigger than Hypsilophodon (H. foxii)

A lot of work has recently been undertaken in a bid to better understand how different Ornithopods were related to each other.  These dinosaurs are characterised by their small, quite triangular heads, large orbits (eye sockets) and relatively primitive dentition (at least when compared to their relatives that comprise the Ankylopollexia clade – more derived Iguanodonts, Camptosaurs and the duck-billed dinosaurs).  Their front limbs tended to be much shorter than their hind limbs, so these dinosaurs were probably bipedal, although capable of dropping onto all fours if needed.  Burianosaurus has been depicted as being very similar to Hypsilophodon (H. foxii), to which it was related.  However, the largest H. foxii thigh bone that we at Everything Dinosaur are aware of, is only about half the size of the holotype of B. augustai.  Based on this we estimate that Burianosaurus was around four metres long.

Size Estimate Burianosaurus Compared to Hypsilophodon

Hypsilophodon and Burianosaurus size comparison.

An approximate size comparison between Burianosaurus and Hypsilophodon (H. foxii).

Picture Credit: Everything Dinosaur

Honouring Burian and Augusta

The genus name honours the famous palaeoartist Zdeněk Burian (1905–1981), whilst the species name refers to the influential palaeontologist and author Josef Augusta (1903 – 1968), who between them, did much to popularise the study of prehistoric animals.  Like Burianosaurus, both Burian and Professor Augusta came from the Czech Republic.  The single fossil bone that represents this new genus (the thigh bone), was found in the Korycany Beds of the Peruc-Korycany Formation.  These are a series of marine deposits laid down in a shallow sea, close to land during the Cenomanian faunal stage of the Late Cretaceous.  Team members at Everything Dinosaur estimate that Burianosaurus lived around 95 million years ago.

In the scientific paper, the researchers carry out  a series of phylogenetic analyses of Ornithopod data and as a result, B. augustai is classified as a basal Ornithopod, however, quite how the Ornithopoda is configured remains open to debate.  If you do ever get the chance to participate in a time-travelling safari to the Cretaceous, look out for these fast-running, bipeds, fossils of which are just as valuable to science as that of any other dinosaur.

The scientific paper: “A Basal Ornithopod Dinosaur from the Cenomanian of the Czech Republic” by Daniel Madzia, Clint A. Boyd and Martin Mazuch published in the Journal of Systematic Palaeontology.

26 09, 2017

California Adopts a State Dinosaur

By | September 26th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Augustynolophus Makes the Grade

The duck-billed dinosaur Augustynolophus morrisi has become the state dinosaur symbol for California. “Auggie” as this Late Cretaceous member of the Hadrosaurinae has been nick-named by campaigners, joins a long list of symbols for the “Golden State”.  Thus, California becomes the eighth state in the Union to adopt a dinosaur as an official state symbol.

Hadrosaur Becomes the State Dinosaur for California

Augustynolophus image.

Augustynolophus has now become California’s dinosaur symbol.

Picture Credit: Augustynolophus Twitter Account

The End of a Long Campaign

It was back in April that Everything Dinosaur first reported on moves within the Californian Senate to adopt a duck-billed dinosaur as a symbol for one of the most populous parts of the United States.  The Assembly member for Santa Monica, Richard Bloom, put forward the legislation for this long extinct reptile to become honoured in this way.  The fossils of this eight to ten-metre-long herbivore come from Upper Cretaceous (Maastrichtian deposits).  The fossil material, including several elements from the skull, have been excavated from marine deposits of the Moreno Formation, strata more frequently associated with Mosasaurs and Plesiosaurs.  It is likely that rivers in spate occasionally washed the carcasses of these dinosaurs out into the sea, the bodies settled on the seabed and were rapidly buried, thus preventing the corpses being broken up by scavengers.  California is the only place in the world where fossils of this particular duck-billed dinosaur have been found.  Two specimens are known, both are part of the vertebrate fossil collection of the Natural History Museum of Los Angeles County.

To read this earlier article: Moves to Adopt a Dinosaur State Symbol for California

Governor Jerry Brown announced earlier this week that the signing of a bill making “Auggie” one of the official insignia of California had taken place.

Once Saurolophus, now Augustynolophus but Always Californian

The first fossil evidence for the dinosaur that was to eventually become the newest Californian state symbol was found in the Panoche Hills of Fresno County in 1939.  A second specimen was excavated from strata in the nearby San Benito County two years later.  The excavation work was undertaken by field teams from the California Institute of Technology.  Both specimens were originally assigned to the Hadrosaur genus Saurolophus, a dinosaur that was first named and described in 1912 from fossils discovered in Canada.

Researchers Excavating the Fresno County Fossil Find (1940)

Augustynolophus excavation.

A field team from the California Institute of Technology excavating the fossils of Augustynolophus.

Picture Credit: Natural History Museum of Los Angeles County

A review of the fossil specimens led to an assignment of a new species within the Saurolophus genus – S. morrisi (2013), however, a more recent reassessment, involving a number of scientists from the Natural History Museum of Los Angeles County, established that there were enough differences in the fossilised bones to permit the establishment of a new genus.  The species name honours Dr William J. Morris, a notable American palaeontologist who did much to improve our understanding of Mesozoic reptiles found in California.  The genus name, which was formally adopted in 2014, pays tribute to Mrs Gretchen Augustyn, a long-time supporter of the Earth sciences and a former Trustee for the Raymond M. Alf Museum of Palaeontology in Claremont, California.

Helping to Spark an Interest in Science, History and Education

Augustynolophus (pronounced Awe-gus-tine-oh-loaf-us), was closely related to Saurolophus, but just three years after being placed into its own genus, the dinosaur has been honoured by becoming one of around thirty state symbols for the most heavily populated state in the Union.  It is not California’s state fossil, that accolade goes to Smilodon californicus, however, after sixty-six million years one of California’s oldest vertebrate residents has been recognised.  Some might think that such insignia are not important, but it is hoped that by raising the profile of the Dinosauria in this way, an interest in science, local history and the story of California will be sparked.

Fossils of Augustynolophus morrisi on Display at the Natural History Museum of Los Angeles County

Augustynolophus fossils

Augustynolophus fossils on display.

Picture Credit: Natural History Museum of Los Angeles County

23 09, 2017

Crunchy Crustaceans and Rotting Wood on the Menu for Dinosaurs

By | September 23rd, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Kaiparowits, Coprolites, Crustaceans and Consumption

This week sees the publication of a new scientific paper that questions the strictly herbivorous diet of Ornithischian dinosaurs.  Writing in the journal “Scientific Reports”, the researchers, which include lead author, Associate Professor Karen Chin, (University of Colorado, Boulder), describe the contents of several coprolites (dinosaur dung), from numerous sites in the Upper Cretaceous Kaiparowits Formation.  Turns out that some hefty Late Cretaceous herbivores were tucking into a smorgasbord of rotting wood, insects and crustaceans, despite the fact that when these dinosaurs lived, approximately 75 million-years-ago, this part of Laramidia was a botanist’s paradise.

Associate Professor Karen Chin Picking at Some Potential Prehistoric Poo

The quest for dinosaur coprolite

Karen Chin (Department of Geological Sciences and Museum of Natural History, University of Colorado Boulder), searching for coprolite.

Picture Credit: University of Colorado, Boulder (Colorado)

Herbivorous Dinosaurs were Not Strictly Herbivores

Direct evidence of the diet of a dinosaur is not usually found, but there is some evidence, plant remains and other matter which is present in the body cavity for example.  Then there is the assessment of tooth wear at the microscopic layer, an analysis such as this when compared to the wear patterns on the teeth of extant animals can prove helpful, but most of our knowledge about dinosaur diet has been inferred from studying their fossilised faeces.  In this new study, the researchers describe the fossilised faecal matter (coprolites) that indicate a recurring consumption of crustaceans and rotting wood.  The scientists conclude that this may have been seasonal behaviour, with female duck-billed dinosaurs seeking out additional calcium and protein to help supplement their diets in preparation for egg laying.  Many species of avian dinosaur (birds), adopt similar feeding strategies today, deliberately selecting food items that contain calcium, copious quantities of which are needed if the female is going to be able to produce healthy, viable eggs.

The Remains of the Shell of a Crustacean Found in the Dinosaur Coprolite

The cuticle of a crustacean found in dinosaur dung.

The black objects represent the exoskeleton of a crustacean within the dinosaur coprolite (scale bar -= 2 mm).

Picture Credit: University of Colorado, Boulder (Colorado)

In mammals, the calcium taste receptor gene has recently been discovered, the same gene may exist in other Tetrapods – birds for instance.  It is also known that taste buds in different species are sometimes co-opted into undertaking different taste functions, so birds and by implication, their extinct close relatives the Dinosauria, might well have had specific calcium detecting sensors on their tongues or elsewhere in their mouths.  There is still a lot we don’t know about eggs of living dinosaurs, (birds) and we must be careful not to draw too many conclusions from this fossil evidence. However, this paper supports similar research undertaken previously, when the coprolites of Ornithischian dinosaurs (seventeen fossilised faeces), were studied from the Two Medicine Formation of the United States.

Which Dinosaur “Dung” It?

The coprolites are similar to those from the Two Medicine Formation, these trace fossils were attributed to the duck-billed dinosaur Maiasaura.  The scientists cannot be certain as to what type of dinosaur produced this Kaiparowits Formation dung, there are a number of potential candidates.  Several bird-hipped dinosaurs are associated with the various bedding planes of the Kaiparowits Formation from which the coprolites were excavated, but which of these produced the dung, which dinosaur “dung” it?

Firstly, the coprolites are large, with some of them having an estimated volume of around ten litres, this rules out a hypsilophodontid, along with the Pachycephalosaur known from this formation.  Whichever type of dinosaur produced the dung, it must have possessed multi-toothed dental batteries capable of handling the coarse diet.  This probably rules out a Thyreophoran (armoured dinosaur).  That leaves three described genera of Ceratopsian – there is a Centrosaurine taxa -Nasutoceratops and two representatives of the Chasmosaurinae, namely Kosmoceratops and Utahceratops.  However, although both Ceratopsians and duck-billed dinosaurs possessed dental batteries, they chewed food in their mouths in different ways.  The scientists studying these coprolites concluded, that their constituents and their similarity to those fossil faeces ascribed to Maiasaura, suggests in all likelihood, that the coprolites were produced by a type of Hadrosaur.  Hadrosaurid bones are the most common body fossil associated with the Kaiparowits Formation and two genera are known, the crested Parasaurolophus (Lambeosaurinae) and the Hadrosaurine Gryposaurus.

Gryposaurus – A Likely Candidate for the Coprolites

Gryposaurus scale drawing.

A scale drawing of the duck-billed dinosaur Gryposaurus.

Picture Credit: Everything Dinosaur

Rotten Wood and Insects

The scientists propose that duck-billed dinosaurs actively sought out rotting wood and ingested this material.  It would have provided a source of carbon and the fungi helping to break down the cell walls might also have provided additional nutrition.  Copious invertebrates would probably have been eaten too.  Many of these herbivores would have accidentally ingested small animals such as insects as they consumed leaves and other plants, but at least ten of the fifteen coprolites examined from three different stratigraphic layers, contained fragments of crustacean shells.  If these were crabs, the carapace of some of the specimens are several centimetres in diameter.  The researchers suggest that these herbivores would have known what they were eating, these fossils can be interpreted as evidence of plant-eating dinosaurs deliberately eating animals.  It might be reasonable to infer that these coprolites reflect a seasonal shift in the diet of herbivores, that might have related to the breeding cycle.  This interpretation of the fossil evidence provides yet another link between non-avian and avian dinosaurs.

Karen Chin summarised the research findings:

“While it is difficult to prove intent regarding feeding strategies, I suspect these dinosaurs targeted rotting wood because it was a great source of protein in the form of insects, crustaceans and other invertebrates.  If we take into account the size of the crustaceans and that they were probably wriggling when they were scooped up, the dinosaurs would have likely been aware of them and made a choice to ingest them.”

A few years ago, we remember seeing fragments of fossilised turtle, stuck between the teeth of a Camarasaurus.  At the time, we thought that this was as a result of the depositional process.  However, perhaps a pre-gravid Camarasaurus may have picked over the carcass of a turtle in a bid to pick up valuable nutrients.

Bits of Fossil Turtle Found in Between the Teeth of a Camarasaurus

Camarasaurus skull with turtle fossils in the teeth.

Camarasaurus skull with turtle fossil fragments in the teeth.

Picture Credit: Peter Larson Black Hills Institute of Geological Research

The scientific paper:  “Consumption of Crustaceans by Megaherbivorous Dinosaurs: Dietary flexibility and Dinosaur Life History Strategies” by Karen Chin, Rodney M. Feldmann & Jessica N. Tashman published in the open access journal “Scientific Reports”.

22 09, 2017

Countdown to TetZooCon 2017

By | September 22nd, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Press Releases|0 Comments

TetZooCon 2017 (October 21st, 2017)

The fourth annual Tetrapod zoology conference (TetZooCon), is rapidly approaching and for those of us used to dealing with deep geological time, the 21st October is coming around really fast!  Playing host to this Everything Dinosaur supported event, is The Venue, Malet Street, London and this year’s agenda is jam-packed with great speakers and super presentations.

TetZooCon – 2017

The TetZooCon logo for 2017

The Tetrapod Zoology Conference (October 21st 2017).

Picture Credit: Darren Naish/John Conway

A Wide Range of Scientific Topics

The organisers have once again provided a rich, diverse and varied range of topics with some notable book signings and a special palaeoart inspired activity that is being kept rather hush-hush for the moment.  If you have an interest in biology, animal behaviour, evolutionary history, ecology, conservation and all other matters related to Tetrapods, this conference is well-worth checking out.  Tickets are £50 per person for the whole day and booking details can be found here: Further Information and Booking Details for TetZooCon 2017.

Renowned palaeoartist, Pterosauria expert and author, Dr Mark Witton will once again be at TetZooCon, attendees will have the opportunity to acquire Dr Witton’s latest book “Recreating an Age of Reptiles”, a publication, Everything Dinosaur was invited to review a few weeks back*.

An illustration of a small herd of Machairoceratops dinosaurs by Mark Witton.

A herd of Machairoceratops dinosaurs making their way to TetZooCon (illustration by Mark Witton).

Picture Credit: Mark Witton

The conference is open to anyone, this not a technical event or one that is only for professionals, if you have a fascination for dinosaurs, enjoy reading about the Earth sciences or an interest in fossils, then TetZooCon is ideal for you.  Last year’s event was a sell-out, so a bigger venue “The Venue” has been chosen this year.  If you like palaeoart, enjoy learning about how scientific discoveries are interpreted and illustrated, then get yourself booked!

One of the event organisers, Darren Naish, will brief conference participants on the latest developments in the world of cryptozoology and another highlight will undoubtedly be Beth Windle’s update on Thylacine research.  This is the fourth TetZooCon and it’s going to be bigger and better than ever.

Everything Dinosaur Supports TetZooCon

Everything Dinosaur has provided a range of great goodies to help support this annual gathering. These will be available as prizes at the end of conference quiz.  One of the prizes donated is the amazing “Them – Age of Dinosaurs” with stunning illustrations by Zhao Chuang and text by Yang Yang and Mark Norrell.   This hardback book outlines the evolution of life using wonderful artwork and the copy we have donated to TetZooCon is the only one in Europe, as far as we are aware.

The Beautifully Illustrated Book – “Them – Age of Dinosaurs”

"Them - Age of Dinosaurs" book.

“Them – Age of Dinosaurs” by Zhao Chaung, Yang Yang and Mark Norrell.

Picture Credit: Everything Dinosaur

“Them – Age of Dinosaurs”

Combining scientific research with vivid prehistoric animal dioramas, life in the Mesozoic is revealed in all its spectacular, multi-coloured glory.  The illustrations are exquisite and this beautiful book might not be printed anymore, its future publication is in doubt.  Attendees at TetZooCon will have the chance to win this amazing prize, along with PNSO Tyrannosaurs and wonderful Rebor models.

One of the Stunning Illustrations from the Book

Amazing dinosaur illustrations.

Fantastic illustrations.

Picture Credit: Everything Dinosaur

A spokesperson from Everything Dinosaur commented:

“We are delighted to support TetZooCon, this is a marvellous event for anyone with an interest in cryptozoology, biology, evolution and everything else covered in that well-written blog Tetrapod Zoology.  We congratulate Darren Naish, John Conway and all those involved in helping to bring about this annual event.”

We have been promised some photos of this year’s activities, presentations and attractions and we are looking forward to posting them up onto our various social media platforms.

The link for further information and to book tickets: Ticket Information and Booking Details

To read Everything Dinosaur’s review of “Recreating an Age of Reptiles”: A Review of “Recreating an Age of Reptiles”

20 09, 2017

Beelzebufo ampinga- Consumer of Dinosaurs

By | September 20th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Giant Prehistoric Frog Capable of Tackling Small Dinosaurs

Ever since it was formally named and described back in 2008, the beach-ball-sized Late Cretaceous frog Beelzebufo (B. ampinga) has fascinated scientists.  The fossil record of frogs (Order Anura), is very poor, although these small, usually unobtrusive creatures have a long evolutionary history.  Imagine the surprise of palaeontologists when they discovered the fossilised remains of a 68 million-year-old monster frog in Upper Cretaceous deposits in Madagascar.

The Late Cretaceous Giant Frog Beelzebufo Compared to an Extant Bull Frog

Beelzebufo (Late Cretaceous) compared to an extant Bull Frog.

Beelzebufo ampinga illustrated.

Picture Credit: Associated Press

It had been speculated that this huge frog could have eaten small dinosaurs.  Writing in the scientific journal “Scientific Reports”, a team of researchers including scientists from the University of Adelaide have concluded that “the frog from hell” had a strong bite capable of tackling relatively large prey, including, potentially, reptiles, birds and mammals.  Small dinosaurs and juveniles of larger species of dinosaur could have been on Beelzebufo’s menu!

Scaling up the Bite Forces from South American Horned Frogs

The vast majority of the frogs and toads alive today have relatively weak jaws.  Most of these amphibians specialise in attacking prey much smaller than themselves such as insects and slugs.   However, one living group of frogs, the South American horned frogs (genus Ceratophrys), are an exception.  These large-mouthed frogs have voracious appetites and their comically big heads allow them to tackle much more substantial prey items.  By scaling up the bite force readings from these types of frogs, the researchers concluded that a frog the size of Beelzebufo could have had a bite force in excess of 2,200 newtons, that’s about twice as much force as a typical adult human can generate when the force of the bite from their molars is assessed.

Measuring the Bite Force of Ceratophrys

Measuring the bite force in extant horned frogs.

An individual Ceratophrys cranwelli biting a force transducer.

Picture Credit: University of Adelaide

One of the paper’s authors, Dr Marc Jones (University of Adelaide) explained:

“Unlike the vast majority of frogs which have weak jaws and typically consume small prey, horned frogs ambush animals as large as themselves, including other frogs, snakes, and rodents.  Their powerful jaws play a critical role in grabbing and subduing the prey.”

The study found that small horned frogs, with a head width of about 4.5 centimetres, can bite with a force of 30 newtons (N) or about 3 kg of pressure.  When these readings were scaled up to take into account much larger extant species, such as the horned frogs from South America, the researchers concluded that for frogs with a head width of around 10 centimetres a bite force of almost 500 newtons could be generated.

Based on their scaling data, the scientists estimated the bite force of the giant extinct frog Beelzebufo may have been up to 2,200 N, comparable to formidable mammalian predators such as female tigers and wolves.

Dr Jones stated:

“At this bite force, Beelzebufo would have been capable of subduing the small and juvenile dinosaurs that shared its environment.”

Persuading Frogs to Bite onto a Custom-made Force Transducer

Corresponding author for the scientific paper, Professor Kristopher Lappin of the Biological Sciences Department, California State Polytechnic University, (California), outlined how the study was undertaken.  The scientists managed to persuade their amphibian subjects to bite down onto leather straps attached to a custom-made force transducer.  This device provided an accurate measurement of the amount of force being applied by the animal.

Professor Lappin said:

“This is the first time bite force has been measured in a frog and speaking from experience, horned frogs have quite an impressive bite and they tend not to let go.  The bite of a large Beelzebufo would have been remarkable, definitely not something I would want to experience.”

It seems those assumptions made by the original researchers back in 2008 were right, based on this evidence Beelzebufo would have been more than capable of snapping up a small dinosaur for dinner.

To read Everything Dinosaur’s 2008 article about the discovery of Beelzebufo and its implications for the radiation of frogs: Beelzebufo – The Frog from Hell

18 09, 2017

Mysterious Dickinsonia Definitely an Animal

By | September 18th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Soft-bodied Dickinsonia – An Animal

The Late Proterozoic saw the evolution of a variety of bizarre, multi-cellular organisms, fossils of which, are extremely rare and what evidence we have, does little to shed light on where on the tree of life these organisms would sit.  Food chains existed but the organisms that made up the biota are so strange and so unlike anything alive today, it’s almost as if palaeontologists looking at Ediacaran fauna are studying life on another planet.  True, Earth back in the Ediacaran geological period (635 to 542 million years ago), was a very different place than it is now.  However, one group of scientists studying one type of Ediacaran organism – Dickinsonia, have confirmed previous studies that place this peculiar disc-shaped organism as definitely belonging to the Kingdom Animalia.  Dickinsonia, looks like nothing alive today, but it has been classified as metazoan, or possibly a placozoan – that puts it in the same Kingdom as you and me.

Dickinsonia – Classified as an Animal

Ediacaran fossils (Dickinsonia)

Dickinsonia confirmed as an animal in new study.

Picture Credit: University of Oregon

What on Earth was Dickinsonia?

Living more than 550 million years ago, Dickinsonia fossils do not resemble any living organism.  It is round or oval in shape, segmented with a distinct “head” and “tail” end, but which was the front and which was the back is debated and whether the terms “head” and “tail” are applicable at all is disputed.  As far as we at Everything Dinosaur are aware, no evidence of a gut or other internal structures have been found.  These fossils, some of which are up to a metre in diameter have been described as early jellyfish, segmented worms, fungi and even an early form of lichen.

Hundreds of examples showing all stages of growth (ontogeny) and in various states of preservation have been found, most famously from the Ediacara Hills in South Australia, from which this geological period is named. In 1946, geologist Reginald Spriggs discovered fossilised imprints in rocks in this area that represent a marine biota, an ancient sea floor.  This was the first known fossil record of multi-cellular life on Earth that predates the Cambrian.  This diverse and exquisitely preserved community of ancient organisms represents a significant snapshot of our planet’s geological heritage, but working out what these fossils represent and where they fit in with the evolution of Cambrian organisms (if they do fit in), is very much open to debate.

In a new study, carried out by scientists at Bristol, Cambridge and Oxford universities in conjunction with the British Geological Survey, strong support is provided for the theory that Dickinsonia was an animal, that it has affinities with the Metazoa, specifically the Eumetazoa plus the Placozoa.  The research is published in the “Proceedings of the Royal Society B”.

Finding a Place in Biology for Dickinsonia

Dickinsonia costata fossil.

The Ediacaran fossil Dickinsonia costata, specimen P40135 from the collections of the South Australia Museum

Picture Credit: Dr Alex Liu (Cambridge University)

The Metazoa are a very basal clade of the Kingdom Animalia.  They are animals that have three types of tissue layer in the embryo and are multi-cellular).  Metazoans are regarded as a sister group to the Porifora (Sponges).  The Placozoa are associated with the metazoans, they are represented by one living genus – Trichoplax and they are flattened, multi-cellular organisms that absorb nutrients through their surface area.

Dr Renee Hoekzema (Oxford University) and one of the authors of the research paper explained:

“Dickinsonia belongs to the Ediacaran biota, a collection of mostly soft-bodied organisms that lived in the global oceans between roughly 580 and 540 million years ago.  They are mysterious because despite there being around two hundred different species, very few of them resemble any living or extinct organism and therefore what they were, and how they relate to modern organisms, has been a long-standing palaeontological mystery.”

The team examined a large number of Dickinsonia fossils, of varying growth stages and applied a quantitative method for plotting the development of the organism, essentially how the animal grew and changed as it got bigger.  An assumption was made as to which fossils represented juveniles and which ones were adults and based on this, the researchers concluded that the growth body plan for Dickinsonia placed it within the Animalia.

This study was undertaken using the principle that growth and development are “conserved” within lineages.  To put it another way, the way a group of organisms grows today would not have changed significantly from the way its ancestors grew hundreds of millions of years ago.

Dickinsonia is composed of multiple “units” that run down the length of its body.  The researchers counted the number of these units in numerous specimens, measured their lengths and plotted these against the relative “age” of the unit, assuming growth from a particular end of the organism.  This data produced a plot with a series of curves, each of which tracked how the organism changed in the size and number of units with age, enabling the researchers to produce a computer model to replicate growth in the organism and test previous hypotheses about where and how growth occurred.

Dr Hoekzema added:

“We were able to confirm that Dickinsonia grows by both adding and inflating discrete units to its body along its central axis.  But we also recognised that there is a switch in the rate of unit addition versus inflation at a certain point in its life cycle.  All previous studies have assumed that it grew from the end where each “unit” is smallest, and was therefore considered to be youngest. We tested this assumption and interpreted our data with growth assumed from both ends, eventually coming to the conclusion that people have been interpreting Dickinsonia as having grown at the wrong end for the past seventy years.”

The First of the Ediacaran Biota to be Described

Dickinsonia was the first organism from the Ediacaran fossil material (Flinders Range), to be described (1947).  Using this computer model, the researchers were able to cross-reference data with studies into how this organism may have moved across the seabed and concluded that it was an early animal, belonging to either the Placozoa or the Eumetazoa.

An Illustration of Life in the Ediacaran Period

Ediacaran marine life.

Life in the Ediacaran.  The brown elongated disc in the centre of the picture is Dickinsonia.

Picture Credit: John Sibbick

Dr Hoekzema went onto state:

“This is one of the first times that a member of the Ediacaran biota has been identified as an animal on the basis of positive evidence.”

The methodology used in this study could be applied to other Ediacaran organisms, so long as there are sufficient fossils to comprise a significant data set.

Co-author Dr Liu stated:

“This finding demonstrates that animals were present among the Ediacaran biota and importantly confirms a number of recent findings that suggest animals had evolved several million years before the “Cambrian Explosion” that has been the focus of attention for studies into animal evolution for so long.  It also allows Dickinsonia to be considered in debates surrounding the evolution and development of key animal traits such as bilateral symmetry, segmentation and the development of body axes, which will ultimately improve our knowledge of how the earliest animals made the transition from simple forms to the diverse range of body plans we see today.”

17 09, 2017

Transforming Brains Require a Transforming Skull

By | September 17th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Bigger Brains of Birds Require Skull Modification

Most scientists agree that a group of dinosaurs, members of the Maniraptora clade, evolved into Aves.  We now have two distinct parts to the Order Dinosauria, the extinct non-avian dinosaurs and their closely related, extant kin, the avian dinosaurs (birds).  A lot of research has been undertaken in a bid to try to understand the evolutionary relationships between reptiles and birds.  The lines between these two groups may be quite blurred, but ironically, although it is accepted that brain size and morphology changed as birds evolved and that the shape of the skull changed too, the specific relationship between regions of the brain and the bones making the skull roof has not been formally tested.

Step forward an international team of scientists, including researchers from Yale University and the Yale Peabody Museum of Natural History, they have concluded that the dramatic dinosaur to dino-bird to true bird transition was accompanied by profound changes in the bones that comprise the roof of the skull.  Plotting the changes in skull bones in the fossil record can provide important insights into the way skulls develop over the Tetrapoda as a whole.

As Birds Evolved from Dinosaurs Skull Shape and Brain Size/Morphology Changed Dramatically

Zhenyuanlong illustrated.

Very probably a ground-dwelling predator – the “dino-bird” Zhenyuanlong.

Picture Credit: Zhao Chuang

Tracking the Link Between Brain Development and Skull Roof Bones

The scientific paper, published in “Nature Ecology and Evolution” this week, represents the first time that scientists have mapped the link between skull bones and brain development.

Assistant Professor Bhart-Anjan Singh Bhullar, co-author of the paper commented:

“Across the dinosaur-bird transition, the skull transforms enormously and the brain enlarges.  We were surprised that no one had directly addressed the idea that the underlying parts of the brain — the forebrain and midbrain — are correlated or somehow developmentally related to the overlying frontal and parietal bones.”

Graduate student, Matteo Fabbri, under the tutelage of Assistant Professor Bhart-Anjan Singh Bhullar at Yale University and the lead author of the scientific paper added:

“Our paper is a milestone in the way of approaching the morphological transition from reptile and dinosaur ancestors to extant birds.”

Looking at the Skull Roof of the Asian Troodontid Zanabazar (Z. junior)

Looking at how the skull roof changed as the brain developed.

The skull morphology of the Asian troodontid Zanabazar (Z. junior).

Picture Credit: Yale University

The picture shows a CT image (computerised tomography), of the skull roof of the Asian troodontid Zanabazar junior, a dinosaur that is closely related to extant birds.  The frontal bone is highlighted in pink and the parietal is shown in green).  The location of the brain is shown in the blueish/purple colour.

Although previous studies had demonstrated a general relationship between the skull and brain development, associations between specific regions of the brain and individual bones that make up the skull roof had remained untested.  This led to conflicting theories on some aspects of skull development within the Tetrapoda.

Assistant Professor Bhullar and his co-workers set out to trace the evolution of brain and skull shape not simply in those members of the Dinosauria closest to birds, but in the entire lineage leading from reptiles to birds.  The team discovered that most reptile brains and skulls were very similar to each other.  It was the dinosaurs most closely related to birds, as well as birds themselves, that were divergent, with enlarged brains and skulls ballooning out around them.

The researchers identified a clear link between the frontal bones and the forebrain and the parietal bones and the midbrain.  This link was confirmed when the embryos of lizards, alligators and birds were examined using a new contrast-stained CT scanning methodology.

CT Scans of Various Tetrapod Skulls (Reptiles to Aves Link)

The link between skull development and brain size.

Examining the history of skull and brain development in the evolution of Aves.

Picture Credit: Yale University

The picture above shows three-dimensional, CT scans of four Tetrapods that represent stages on the reptile to bird evolutionary line.  The frontal bone is shown in pink, the parietal is depicted in green and the brain is once again shown as a blueish/purple object.  A chicken skull (top), is compared to its close dinosaurian relative, the troodontid Zanabazar (second from top).  A skull of the primitive, Late Triassic dinosaur* Herrerasaurus is shown below the skull of Zanabazar.  At the bottom, is the skull of Proterosuchus, an Early Triassic Archosauriform that is believed to be an ancestral form that diverged before the crocodile (Crurotarsi – crocodilians et al) and the bird (Ornithodira – dinosaurs, Pterosauria, Aves et al) split.

Bhullar added:

“We suggest that this relationship is found across all vertebrates with bony skulls and indicates a deep developmental relationship between the brain and the skull roof.  What this implies is that the brain produces molecular signals that instruct the skeleton to form around it, although we understand relatively little about the precise nature of that patterning.  Ultimately, one of the important messages here is that evolution is simpler and more elegant than it seems.  Multiple seemingly disparate changes — for instance to the brain and skull — could actually have one underlying cause and represent only a single, manifold transformation.”

*dinosaur Herrerasaurus – the exact phylogenetic relationship between the Herrerasauridae and the Dinosauria remains unclear.  Herrerasaurids comprise of a group of Archosaurs that show a number of dinosaurian and non-dinosaurian traits.  In a recent (2017), revision of the Dinosauria, the Herrerasauridae was classed as a sister clade to the Sauropodomorpha and placed outside of the Ornithoscelida (Theropods and Ornithischians).  Whether Herrerasaurus is a member of the Dinosauria remains open to debate.

Everything Dinosaur acknowledges the help of a press release from Yale University in the compilation of this article.

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