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

18 11, 2018

Very Rare Dinosaur Fossil Find in Oregon

By | November 18th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

An Oregon Ornithopod

There may be many famous dinosaurs known from the United States of America, after all, when it comes to naming dinosaurs, Tyrannosaurus rex, Stegosaurus and Triceratops tend to trip off the tongue, but America’s dinosaur fossil heritage is not uniform across the whole country.  Several parts of the U.S. have no record of dinosaur discoveries, and numerous others have a very fragmentary record when it comes to the preserved remains of Dinosauria.  Oregon, the ninth largest State in terms of area, has a very poor dinosaur fossil record, however, a newly described fossil discovery made in the eastern part of the “Beaver State”, has got palaeontologists quite excited about the prospect of more dinosaur fossil finds being made.

The Toe Bone from a Dinosaur (Ornithopoda)

Writing in the “Journal of Vertebrate Palaeontology”, scientists from the University of Oregon in collaboration with the University of Calgary (Canada), have published a paper on the discovery of a single toe bone from a plant-eating dinosaur – an extremely rare find considering that this part of north-western North America was underwater throughout most of the Mesozoic Era.

Various Views of the Single Dinosaur Toe Bone (Pedal Phalanx)

Indeterminate pedal phalanx (Oregon dinosaur).

Views of the single dinosaur toe bone discovered in eastern Oregon.

Picture Credit: University of Oregon

The fossil bone was found by University of Oregon Earth Sciences Professor Greg Retallack during field work in 2015, near the town of Mitchell (Wheeler County, eastern Oregon).  The single bone was spotted amongst mollusc fossils exposed on a slope consisting of marine shale.  The fossil dates from the Albian fauna stage of the Cretaceous and is the first ever Oregon dinosaur fossil to be the subject of a paper in a peer-reviewed scientific journal.  Furthermore, it represents the first dinosaur fossil find from Oregon from strata not regarded as Upper Cretaceous.

Oregon might be bigger than the whole of the United Kingdom, but the Mesozoic-aged exposures represent marine sediments, that harbour very few remains of ancient terrestrial animals.

Greg Retallack stated:

“Oregon landscapes are rich with Cretaceous rocks, but they rarely contain the kinds of dinosaur remains we see elsewhere in the United States.  The rocks here are the right age but are mostly from under the sea where dinosaurs did not live or from swamps where dinosaur bones are seldom preserved.”

Not Able to Assign a Genus

Although, identified as a dinosaur bone (pedal phalanx), it is not possible to assign it to a specific species or genus, although the research team are confident that it came from a plant-eating Ornithopod dinosaur.

An Illustration of a Typical Ornithopod Dinosaur

Burianosaurus augustai illustrated.

An illustration of a typical member of the Ornithopoda – the basal Ornithopod from the Czech Republic – Burianosaurus augustai.

Picture Credit: Edyta Felcyn

Co-author of the paper, Edward Davis (University of Oregon), explained that the remains of a terrestrial animal ended up in the mollusc bed, after having been swept out to sea.

He explained:

“It’s a phenomenon we sometimes call “bloat and float”.  That is, the animal died on shore in its terrestrial habitat, then was washed out to sea, where it floated while bloated with decomposition gasses.  Eventually it burst, and only this toe bone was entombed and became a fossil.”

A Sizeable Plant-eating Dinosaur

Although very little taxonomic information can be gained from a single, isolated toe bone, a size comparison with much more complete and better known Cretaceous Ornithopods such as Tenontosaurus, suggests that this dinosaur may have been about six to seven metres long and weighed around a tonne.

A spokesperson from Everything Dinosaur commented:

“Although such a fossil find in marine sediments is exceptionally rare, it just goes to show that dinosaurs fossils can be found and if there is one, then there may be more. Many of the Mesozoic-aged rocks in this part of Oregon represent near coastal marine deposits.  Given that dinosaurs would have roamed the land close to the sea for millions of years it is possible that more dinosaur remains might be found.”

To read an article published by Everything Dinosaur in 2015, which looks at which part of the United States are not associated with dinosaur fossils: Washington State the 37th U.S. State with a Dinosaur.

14 11, 2018

Fossil Bird from Late Cretaceous Utah – Deepens a Mystery

By | November 14th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Mirarce eatoni – Deepens the Mystery Over Late Cretaceous Avian Extinctions

All living birds from Albatrosses to Zebra finches belong to one group of avians – the Neornithes.  Our feathered friends share a number of key anatomical traits that defines them as a group from the smallest such as the Bee Hummingbird to the largest living bird, the Ostrich.  However, back in the Cretaceous, things were very different.  There were several different taxa of birds including the very diverse and highly successful Enantiornithines that shared the skies with early members of the Neornithines, but only the ancestors of today’s extant birds survived the end-Cretaceous extinction event and that’s a puzzle for palaeontologists.

The puzzle has just become a little more complex with the publication of a scientific paper in the on-line, open access journal “PeerJ”.  This paper describes the fossilised remains of an Enantiornithine that lived around 75 million years ago, in Utah (USA).  This prehistoric bird, about the size of a Raven, has been named Mirarce eatoni and its fossils show that it was probably a match for most modern birds in terms of its aerial abilities.

Perched on the Horns of a Utahceratops (Mirarce eatoni)

Mirarce eatoni - life reconstruction.

An illustration of the Late Cretaceous enantiornithine Mirarce eatoni.

Picture Credit: Brian Engh

This leads to one very intriguing question, if Enantiornithines like Mirarce were so advanced, then why after the Cretaceous-Palaeogene mass extinction event did only one group of birds survive?

A Complete Anatomical Description

The fossil material consists of several neck bones (cervical vertebrae), back bones (dorsal vertebrae), the fused caudal vertebrae making up the pygostyle, elements from the limbs, parts of the hips, a partial scapula, coracoid, the furcula (wishbone) and several other fragmentary elements including the radius and ulna.  This represents a veritable treasure trove of North American Enantiornithine fossils for palaeontologists to study, most North American members of this taxon are known from very scrappy fossil remains, mostly consisting of isolated fused leg bones and toes.  All in all, about 30% of the total skeleton is known and crucially, unlike most of the more complete Enantiornithine specimens from the Lower Cretaceous deposits of China, this specimen, is preserved in three-dimensions, it has not been crushed as flat as a pancake.  The excellent state of preservation and the number of fossil bones has permitted the researchers to undertake a complete anatomical description.

A Skeletal Reconstruction of the Newly Described North American Enantiornithine Mirarce eatoni

Mirarce eatoni skeletal reconstruction.

A skeletal reconstruction of the Enantiornithine Mirarce eatoni from Late Cretaceous Utah.  The bones shaded white represent known fossil material.  Note, cranial material is not known.

Picture Credit: Scott Hartman

The “Kaiparowits Avisaurid”

The specimen was originally discovered back in 1992, by University of California, Berkeley palaeontologist Howard Hutchinson, whilst he was exploring Kaiparowits Formation deposits for evidence of turtles.  It was quickly identified as an Enantiornithine and ascribed to the Avisauridae family, a family of prehistoric birds known from South America, North America, parts of Europe, Siberia and the Middle East (Lebanon).  The partial skeleton (UCMP 139500), was nicknamed the “Kaiparowits avisaurid”.   Although, its significance was noted, after all, the fossils represent the most complete example of an Enantiornithine ever found in North America, it remained undescribed.  All that changed when PhD student Jessie Atterholt (University of California, Berkeley), was given the opportunity to provide a formal scientific description.

Research Suggests that Mirarce eatoni was a Strong Flier and Well-Adapted to Life in the Late Cretaceous

Mirarce eatoni - life reconstruction.

A close-up view of the newly described Late Cretaceous bird Mirarce eatoni (colouration and plumage speculative).

Picture Credit: Brian Engh

A Strong and Capable Flier

In collaboration with her colleague Howard Hutchinson and with the support of Jingmai O’Connor, from the Chinese Academy of Sciences and an authority on Cretaceous fossil birds, a complete analysis of the fossil bones was undertaken.  This study revealed that M. eatoni possessed several of the same physical adaptations for highly refined powered flight that modern birds (Neornithines) have.

Fossils of Enantiornithines from the Lower Cretaceous of China, birds such as Confuciusornis sanctus show a mix of basal and more advanced anatomical traits.  For example, the breast bone (sternum), of C. sanctus, is relatively small.  Modern birds have a deeply keeled sternum, this allows the attachment of large muscles to aid powered flight.  The wishbone (furcula) of Confuciusornis and most other Early Cretaceous Enantiornithines, is little more than a curved bar.  However, the furcula of M. eatoni is shaped much more like the “V-shaped” wishbones of modern birds.  The furcula of Mirarce would have been able to flex and to store energy released during the flapping of the wings.

Commenting on the significance of these anatomical characteristics, Atterholt stated:

“We know that birds in the early Cretaceous, about 115 to 130 million years ago, were capable of flight but probably not as well adapted for it as modern birds.  What this new fossil shows is that Enantiornithines, though totally separate from modern birds, evolved some of the same adaptations for highly refined, advanced flight styles.”

The Furcula (Wishbone) of Mirarce eatoni

The furcula of Mirarce eatoni.

Two views of the wishbone (furcula) of Mirarce eatoni (A) dorsal and (B) ventral with line drawings.  Scale bar = 1 cm.

Picture Credit: PeerJ

Quill Knobs?

A close examination of the right ulna (lower arm bone), revealed evidence of two roughened patches preserved on the shaft of the bone.  These rough patches were interpreted as being attachment sites for quill knobs, that anchor the wing feathers to the skeleton and to help strengthen the wings for use in active, prolonged, powered flight.  Quill knobs are found in living birds.  This is the first time that such a feature has been seen in an Enantiornithine and indicates that Mirarce was, very probably, a strong flier.

Potential Quill Knobs Identified in an Enantiornithine (M. eatoni)

Quill knobs on an Enantiornithine.

Roughed structures on the ulna of Mirarce compared to the quill knobs found on the ulna of a Pelican.

Picture Credit: PeerJ

If these structures are quill knobs, then this suggests that this anatomical trait evolved in parallel with members of the Dinosauria (dromaeosaurids and other maniraptorans along with the ornithomimids) and in parallel with a number of types of prehistoric bird.

How Did Mirarce Get Its Name?

The genus name reflects that fantastic state of preservation of the fossil material (Latin “mirus” for wonderful) and after Arce, the winged messenger of the Titans in Greek mythology.  The trivial name honours Dr Jeffrey Eaton, in recognition of his work studying the vertebrates of the Kaiparowits Formation.  A spokesperson from Everything Dinosaur commented that this prehistoric bird’s name was pronounced “mere-ark-ee ee-tow-eye”.

But Why Did These Advanced Enantiornithines Die Out?

If Late Cretaceous Enantiornithines were just as advanced as modern birds, then, why did they die out with the non-avian dinosaurs while the ancestors of modern birds survived the extinction event?

Atterholt, who has moved onto a position of Assistant Professor and human anatomy instructor at the Western University of Health Sciences in Pomona (California), added:

“This particular bird is about 75 million years old, about 10 million years before the die-off.  One of the really interesting and mysterious things about Enantiornithines is that we find them throughout the Cretaceous, for roughly 100 million years of existence and they were very successful.  We find their fossils on every continent, all over the world, and their fossils are very, very common, in a lot of areas more common than the group that led to modern birds.  Yet modern birds survived the extinction while Enantiornithines go extinct.”

Forest Dwellers Versus Seed Eaters

A number of ideas have been put forward to help explain why some types of birds survived the end-Cretaceous mass extinction event whilst others did not.  For example, one hypothesis proposes that Enantiornithines were forest dwellers and when the asteroid strike/volcanism resulted in a dramatic loss of woodland habitats, these types of birds suffered more than other birds that lived in different environments.

The absence of cranial material prevents the researchers from investigating what Mirarce might have eaten.  Most known members of the Enantiornithes had teeth in their beaks and Mirarce supports the idea that these types of birds gradually got larger over time, but what this bird ate remains a mystery.  If it had been a predator of small vertebrates and insects, any major disruption to the food chain could have led to extinction.  However, a paper published in 2016 proposed that birds with toothless beaks such as the early Neornithines could have survived the extinction event by eating seeds that persisted in the soil.

To read more about this paper: Seed Eating May Have Helped the Birds Survive

The scientific paper: “The Most Complete Enantiornithine from North America and a Phylogenetic Analysis of the Avisauridae” by Jessie Atterholt, J. Howard Hutchinson and Jingmai K. O’Connor published in PeerJ.

13 11, 2018

Getting to the Bottom of Ornithischian Teeth

By | November 13th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Scientists Sink Their Teeth into Toothy Dinosaur Problem

Two of the most successful lineages of Ornithischian dinosaurs are the Ceratopsians (horned dinosaurs) and the Hadrosaurs (duck-billed dinosaurs).  These herbivores dominated the megafauna of many Late Cretaceous environments and one of the reasons for their success was their remarkable dental batteries.  Although horned dinosaurs and duck-bills processed plant food in their mouths differently, (they had different chewing and grinding actions), the rows of teeth permitted these types of plant-eaters to process the toughest vegetation extremely efficiently

The Dental Battery of a Typical Hadrosaurid

Typical Hadrosaur dental battery.

These teeth were made for grinding. The rows and rows of tough teeth in the jaw of a hadrosaurid – the dental battery.

Picture Credit: Dr Gregory Erickson

However, the evolution of these dental batteries is poorly understood, so a team of Canadian and Chinese scientists set out to examine how this dentition may have come about.  To do this they examined the teeth morphology and jaws of a little Ornithopod from north-eastern China called Changchunsaurus parvus.  This light-weight dinosaur that measured around 1.5 metres in length, is known from several skulls and other postcranial material from Jilin Province (China).

A Life Reconstruction of the Ornithopod Changchunsaurus (C. parvus)

Changchunsaurus Life Reconstruction

An illustration of the Chinese Ornithopod Changchunsaurus. Note scale bar = 1 metre.

Picture Credit: Everything Dinosaur

How Did “Typical” Ornithischian Dentition Develop?

Writing in the academic, on-line journal “PeerJ”, the researchers from Jilin University and the University of Alberta, describe how thin slices were taken from five jaw bones of this dinosaur so that teeth in the jaw could be studied.  In addition, the slices once polished to show their internal structure, would help the researchers determine tooth composition and to see how the teeth are maintained throughout the life of this little dinosaur.  Changchunsaurus makes a good candidate for this type of work, as it is known from numerous skulls (albeit, some of them are quite distorted), and it is regarded taxonomically as being close to origins of the Ornithopoda.

One of the Skulls of Changchunsaurus parvus Used in the Study

The holotype of Changchunsaurus parvus.

Image of the skull of the holotype specimen of C. parvus (JLUM L0304-j-Zn2).  The skull is shown in lateral view and the yellow shaded area indicates the area of the jaw from which the samples were taken.  Scale bar = 2 cm.

Picture Credit: Chen et al (PeerJ)

A Unique Method of Tooth Replacement

Among the notable features of Changchunsaurus parvus dentition is a unique method of tooth replacement that allowed this herbivore to recycle teeth without disrupting the continuous shearing surface formed by its tooth rows.  This permitted Changchunsaurus to have an efficient tooth-grinding surface all the time, thus helping it to process tough plant material.  The scientists also discovered that the teeth feature wavy enamel, a tissue type formerly thought to have evolved only in more derived members of the Ornithopoda.  The wavy enamel of Changchunsaurus is the phylogenetically earliest occurrence of this type of tissue known.

A Section of Dentary (Lower Jaw) Sample Along with Cross-sections of Teeth Showing Morphology

Changchunsaurus tooth morphology.

(B) a partial dentary showing the area cross-sectioned and magnified cross-sections of teeth (C to F) identifying teeth replacement and tooth morphology.

Picture Credit: Chen et al (PeerJ)

The picture above shows (B), an image of one of the partial lower jaws used in this research.  The purple line shows the plane of sectioning.  A whole view image of one of the thin sections through the lower jaw is shown (C) and (D) shows a magnified view of the process of tooth replacement.  Images (E) and (F) show highly magnified views of identified wavy enamel on the crown of replacement teeth (labial and lingual margins).

Commenting on the significance of this study, lead author Professor Chen Jun stated:

“These tissue-level details of the teeth of Changchunsaurus tell us that their teeth were well-adapted to their abrasive, plant-based diets.  Most surprisingly, the wavy enamel described here, presumably to make it more resistant to wear, was previously thought to be exclusive to their giant descendants, the duckbilled dinosaurs.”

This research contradicts previous interpretations that this type of wavy enamel arose in association with more complex hadrosauroid dentitions.  In view of its early appearance, the research team suggests that wavy enamel may have evolved in association with a shearing-type dentition in a roughly symmetrically-enamelled crown, although its precise function still remains somewhat of a mystery.

The authors suspect these features may have arisen early on in the Ornithopoda as they became adapted to herbivory, having to process tough vegetation.

The scientific paper:

“Tooth Development, Histology, and Enamel Microstructure in Changchunsaurus parvus: Implications for Dental Evolution in Ornithopod Dinosaurs” by Jun Chen , Aaron R. H. LeBlanc , Liyong Jin, Timothy Huang and Robert R. Reisz published in PeerJ.

5 11, 2018

Super Efficient Lungs Powered Dinosaur Success

By | November 5th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Bird-like Lungs Could Have Helped Dinosaurs to Dominate

There has been a great deal of debate regarding the rise of the Dinosauria.  How and when did these relatively unassuming members of the Dinosauria, which only made up a small proportion of terrestrial biota during the Middle Triassic, rise to dominance, out-competing a host of other reptilian groups?  The respiratory system of dinosaurs could provide a clue.  In a new study publised in the open access journal of the Royal Society (Royal Society Open Science), a team of researchers postulate that the lung-air sac system could have helped dinosaurs thrive in Earth’s oxygen-depleted atmosphere.

Did a Super-efficient Pumonary System Help the Dinosaurs to Thrive?

Dinosaurs probably had a super-efficient respiratory system.

New research suggests super-efficient dinosaur lungs assisted the rise of the Dinosauria.

Picture Credit: Chinese Academy of Sciences

Studying the Breathing Systems of Modern Birds and Alligators

Birds have a super-efficient respiratory system that is unique amongst the vertebrates.  However, palaeontologists remain uncertain as to when the avian-style lung evolved.  Did it evolve in dinosaurian ancestors or is it restricted to birds?  After all, if you are going to fly, then you need a very efficient and powerful set of lungs to get enough oxygen to your flight muscles.

This area of anatomy has attracted a great deal of debate.  Recently, Everything Dinosaur reported on a study conducted on a specimen of Archaeorhynchus spathula, a primitive bird (basal member of the Ornithuromorpha), from the Lower Cretaceous of China, that may show preservation of an advanced avian lung.  To read more about this research: Breathing Life into the Bird Lungs Debate

The scientists, including researchers from the University of Manchester, compared dinosaur lungs to those of living crocodilians and the lungs of extant birds.  Lead researcher, PhD student Robert Brocklehurst (School of Earth and Environmental Sciences, Manchester University), stated:

“The respiratory system of non-avian dinosaurs has been the topic of considerable study over the years, both in an attempt to shed light on the biology of now extinct members of the dinosaur family, and in order to understand the origins and evolution of modern birds and reptiles.”

Low Oxygen Levels in the Triassic and Early Jurassic

Today, our atmosphere contains approximately 21 percent oxygen, however, things have not always been like that.  During the Middle Triassic, through to the Early Jurassic, a time that saw the evolution and the radiation of the Dinosauria, the atmospheric oxygen percentage of our planet fell to around 15-17%.   With less oxygen in the air, a group of vertebrates with more efficient lungs would have had a definite evolutionary advantage over other terrestrial animals.

During the Triassic A Wide Variety of Terrestrial Reptilian Vertebrates Co-existed

The flora and fauna of the Late Triassic.

Dinosaurs, Aetosaurs, Phytosaurs and and Rauisuchians co-existed in the Triassic, but did super-efficient lungs help the Dinosauria to become dominant.

Picture Credit: Victor Leshyk

To investigate the different kinds of respiratory systems the team used Computerised Tomography (CT) scans to look at the lung cavities of four modern crocodilians and twenty-nine modern birds, including the largest living bird today, the ostrich and compared their structure with those of sixteen different dinosaur species.  The detailed scans revealed that all the dinosaurs had vertebrae more similar in shape to those of birds than those of crocodilians.  In addition, the scientists discovered that the dinosaur vertebrae jutted into the lung cavity, the same as found in living birds.

Robert explained:

“We thought some of the dinosaurs would have lungs more like birds, and others would be similar to reptiles, but this wasn’t the case at all.  Every dinosaur sample we scanned just looked like the birds we scanned.”

Dissection Used in this Study

As well as using CT scans, the team removed the lungs of an alligator and an ostrich, and found the skeletal support structures surrounding the lungs were very different in each animal.  The alligator’s lung cavity was smooth and allowed the lungs and other internal organs to glide as they move to pump air in and out while the animal swims.  However, the ostrich lung cavity was found to be furrowed, similar to the anatomical condition found in the dinosaurs.

The scientists concluded that having more efficient bird-like lungs permitted the dinosaurs to adapt and thrive in an oxygen depleted environment, whereas other groups including the the Crurotarsi clade of Archosaurs that gave rise to modern crocodiles, struggled.

Commenting on the research, co-author Professor Bill Sellers (Manchester University) added:

“If even the very first dinosaurs to evolve had bird-like lungs, this goes some way to explaining why dinosaurs became the dominant animal species of their time.  Other animal groups simply may not have had lungs as well suited to extracting oxygen from the air.  That simple evolutionary difference may have let dinosaurs rule world.”

The scientists concluded that respiratory and pulmonary modifications would have provided dinosaurs with more efficient means of oxygen uptake relative to other vertebrates during the environmentally hypoxic conditions which pervaded much of the early part of the Mesozoic.  This anatomical advantage enjoyed by the Dinosauria could thus potentially have contributed to their radiation and dominance over terrestrial ecosystems, which was to last for around 150 million years.

The Lungs of Dinosaurs Helped to Power Their Evolutionary Success

The sophisticated respiratory system of Ingentia prima.

The air sacs of Ingentia prima (green) the lungs shown in brown.  This large, Early Jurassic Sauropod had a super-efficient respiratory system.

Picture Credit: Jorge A. González

Everything Dinosaur acknowledges the assistance of a press release from Manchester University in the complilation of this article.

The scientific paper: “Vertebral Morphometrics and Lung Structure in Non-avian Dinosaurs” by Robert J. Brocklehurst, Emma R. Schachner and William I. Sellers published in Royal Society Open Science.

4 11, 2018

A New Species of Rebbachisaurid is Named

By | November 4th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Lavocatisaurus agrioensis – A New Long-Necked Dinosaur from Argentina

A team of palaeontologists from Argentina and Spain have announced the discovery of a new species of long-necked dinosaur from the Early Cretaceous of Argentina.  The dinosaur, represented by a set of bones that indicate the remains of at least three individuals, has been named Lavocatisaurus agrioensis and it will help to shed more light on a rare and enigmatic group of Sauropods known as the rebbachisaurids.

A Skeletal Reconstruction and Photographs of Key Fossils from L. agrioensis

Skeletal reconstruction and fossil bones attributed to Lavocatisaurus agrioensis.

Skeletal reconstruction based on the holotype and paratype specimens of Lavocatisaurus agrioensis.  Scale bars = 10 cm.

Picture Credit: AFP/Agencia CTYS

The picture above shows the skeletal drawing of the adult dinosaur with illustrations of key bones from the excavation.  Most of the neck and the skull has been recovered.  Cranial fossils associated with the Rebbachisauridae are rare, the discovery of these specimens from Agrio del Medio (Neuquén Province, Argentina) will help scientists to better understand taxonomic relationships amongst members of this Sauropod family, largely associated with Gondwanaland fossil deposits.

Fossils of a Family Group?

Writing in the journal “Acta Palaeontologica Polonica”, the scientists report the discovery of one large, presumably adult animal with two smaller sub-adults found in association.  The fossil material come from terrestrial sandstone deposits laid down around 110 million years ago (Aptian to Albian faunal stage of the Early Cretaceous), in an arid environment with isolated oasis and other water sources (Rayoso Formation).

One of the authors of the scientific paper, José Luis Carballido, of the Egidio Feruglio Museum (Argentina), stated:

“We found most of the cranial bones: the snout, the jaws, a lot of teeth, also the bones that define the eye sockets for example and in that way, we were able to create an almost complete reconstruction.  Not only is this the discovery of a new species in an area where you wouldn’t expect to find fossils, but the skull is almost complete.”

The fossils represent one large dinosaur estimated to be around twelve metres in length and two smaller animals around six to seven metres in length.  The research team postulate that this could represent a family group that lived together and perished together, perhaps unable to find a water source in a time of drought.

Preparing to Move Some of the Fossil Material (Lavocatisaurus)

Fossils of Lavocatisaurus are prepared for removal.

The jacketed remains of one of the Lavocatisaurus specimens is prepared for transport away from the dig site.

Picture Credit: AFP/Agencia CTYS

Lead author of the paper, José Ignacio Canudo (Zaragoza University, Spain) added:

“This discovery of an adult and two juveniles also signifies the first record of a group displacement among the Rebbachisaurus dinosaurs.”

The Rebbachisauridae Family

The Rebbachisauridae family of Sauropods are a group of basal members of the Diplodocimorpha clade that includes more famous Late Jurassic dinosaurs such as Diplodocus, Apatosaurus and Brontosaurus.  The rebbachisaurids are known from both Lower Cretaceous and Upper Cretaceous strata and had a wide geographical distribution throughout Gondwana and southern Laurasia with fossils reported from north and central Africa as well as South America and Europe (Spain).

An Illustration of a Typical Rebbachisaurid Dinosaur (R. garasbae)

Rebbachisaurus scale drawing.

Scale drawing of Rebbachisaurus (R. garasbae)

Picture Credit: Everything Dinosaur

3 11, 2018

Elaborate Plumage in Confuciusornis

By | November 3rd, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Patterns on the Feathers of Confuciusornis as Complex as Modern Birds

A team of international scientists, including researchers from the China University of Geosciences (Beijing), the University of Ghent (Belgium) and the University of Texas at Austin (United States), have discovered that the patterns on the feathers of an Early Cretaceous bird may have been very similar to and as complex as the patterns seen on the feathers of extant Aves.  Writing in the academic, on-line journal “PeerJ”, the researchers conclude that the patterning of Confuciusornis feathers probably performed similar functions to the patterning on modern bird’s feathery coats, that is, they provided camouflage and also played a role in display.

Confuciusornis Integumentary Covering – Elaborate Plumage

Study suggests Confuciusornis had elaborate plumage.

Reconstruction of the plumage of Confuciusornis (specimen number CUGB P140).

Picture Credit: Li et al (PeerJ)

Complex Patterning Detected by Sophisticated Chemical Analysis

The specimen studied consists of a slab and counter slab of a single, individual bird from Early Cretaceous deposits in Fengning County, Hebei Province (north-central China).  The fossils are from the vertebrate collection of the China University of Geosciences and represent an example of Confuciusornis sanctus.  The research team identified exceptional feather preservation but poor preservation of the bones, the unusual state of preservation permitted the scientists to identify melanin signals in the fossilised feathers indicating a complex patterning of spots on the wings, throat and on the tuft of feathers at the back of the head forming a small crest.  The shape of the structures that form these patterns in conjunction with chemical analysis confirmed the diagnosis of the pigment melanin.  However, specific colouration associated with the patterns could not be discerned.

The Slab and Counter Slab or a C. sanctus Specimen Reveals Complex Patterning on the Plumage

Evidence of Confuciusornis plumage.

Evidence of plumage diversity in the Confuciusornithidae from the new specimen (CUGB P1401).

Picture Credit: Li et al (PeerJ)

The photograph (above) shows various views of the main slab of the fossil specimen showing details of the plumage.  The dots in (A) indicate places that were subjected to sampling, whereas B and C reveal the crest located on the back of the head.  Parts D and E show elements of the integumentary covering in close detail.

Using a range of analytical techniques including scanning electron microscopy and ion mass spectrometry (ToF-SIMS) the researchers concluded that the elaborate spotting on this specimen exceeds that found in exceptionally-preserved troodontids and compsognathids and rivals that in modern birds, suggesting that plumage patterns evolved greater complexity through avian evolution.

The exact age of the strata is uncertain, although it is believed that the deposits from Fengning County are approximately equivalent in age with the Dawangzhangzi Member of the Yixian Formation, around 122-123 million years old (Aptian faunal stage of the Early Cretaceous).  The data from this study suggests that Confuciusornis had more complex patterning than the patterning identified in Achiornis or in the stripes of the compsognathid Sinosauropteryx.  The research team conclude that this specimen of a primitive bird provides evidence to support the idea that complex patterning of feathers evolved at a relatively early stage in avian evolution.

The Link to Barn Owls

Integumentary patterns and colours play a variety of roles in living birds.  Such patterning in fossil specimens probably performed the same sort of functions and in addition, they can help to inform on the habitat in which the extinct creature lived.  In some modern bird groups, barn owls for example (Strigiformes), it has been observed that the size and placement of the spots on the feathers play a role in mate selection.  Male barn owls tend to prefer females with larger spots.  The patterning identified on this C. sanctus specimen leads to the intriguing idea that for confuciusornithids, just like barn owls, the location and the size of the spots on the plumage played a role in choosing a mate.

The scientific paper: “Elaborate Plumage Patterning in a Cretaceous Bird” by Quango Li, Julia A. Clarke, Ke-Qin Gao, Jennifer A. Peteya and Matthew D. Shawkey published in PeerJ.

30 10, 2018

A New Azhdarchid Pterosaur from France

By | October 30th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Mistralazhdarcho maggii – From the Upper Cretaceous of France

A team of scientists based in France and Belgium have announced the discovery of a new species of pterosaur from Upper Cretaceous rocks in south-eastern France (Bouches-du-Rhône).  The fragmentary bones have been assigned to the Azhdarchidae family of pterosaurs, one of the last groups of flying reptiles to exist and a family that contains giants such as Quetzalcoatlus and Hatzegopteryx.  With a wingspan estimated to be around 4.5 metres, the specimen, believed to be a juvenile, provides evidence of a third azhdarchid pterosaur size class from the cluster of islands that represented continental Europe towards the end of the Mesozoic.

The pterosaur has been named Mistralazhdarcho maggii pronounced (miss-tral-ads-dar-cho may-gee).

A Life Reconstruction of the Newly Described French Azhdarchid Pterosaur – Mistralazhdarcho maggii

Life reconstruction of the pterosaur Mistralazhdarcho maggii.

An illustration of the newly described (2018) azhdarchid pterosaur from France Mistralazhdarcho maggii.

Picture Credit: Pierre Lavaud

One of the Most Complete Pterosaur Fossils Known from Late Cretaceous Europe

Writing in the academic publication the “Journal of Vertebrate Paleontology”, the researchers describe the finding of part of a lower jaw, a neck bone and several other postcranial bones in 2009.  The bones were found in association with each other and therefore, probably represent the fossilised remains of a single pterosaur.  The material comes from the excavation site of Velaux, near Aix-en-Provence and from strata that dates to the Campanian faunal stage of the Late Cretaceous.

Views of the Fossil Material Ascribed to the New Pterosaur Mistralazhdarcho maggii

Mistralazhdarcho maggii fossil material.

Fossil material associated with the newly described French pterosaur Mistralazhdarcho maggii.

Picture Credit: Royal Belgian Institute of Natural Sciences

The photograph (above), shows a part mandible (a) with a distinctive ridge (mandibular symphysis).  A cervical vertebra (b), left humerus (c), left radius (d) and two bones from the hand – metacarpal IV (e) and a finger bone (f).

Although the fossil material is fragmentary, such is the poor fossil record of Late Cretaceous pterosaurs from Europe that these few bones make Mistralazhdarcho one of the most complete European azhdarchids described to date.  In addition, Mistralazhdarcho is the first partial skeleton of a flying reptile excavated from Upper Cretaceous deposits of western Europe.

Related to a North African Pterosaur?

The scientists, which included researchers from the University of Rennes, the Royal Belgian Institute for Natural Sciences and Poitiers University, conclude that Mistralazhdarcho was related to an earlier pterosaur called Alanqa (A. saharica), which lived in North Africa around 95 million years ago.  When Alanqa was first described, back in 2010, it was assigned to the Azhdarchidae, but more recent studies incorporating skull material discovered in 2015, have cast doubt on the taxonomic position of Alanqa.

To read about the discovery of Alanqa saharicaDublin Team Announce the Discovery of a New Pterosaur

An Adult Probably Had a Wingspan of Around 5-6 metres

Examination of the fossil bones suggest that they were not fully ossified and that this was a sub-adult.  The researchers speculate that a fully-grown Mistralazhdarcho would have had a wingspan of around 5 to 6 metres, possibly even bigger.  This size estimate is in between the size estimates given for the two azhdarchids from the Maastrichtian of Romania (Hateg Formation), which also represents the European Late Cretaceous archipelago environment.

A Size Comparison of European Azhdarchid Pterosaurs

European azhdarchid pterosaur comparison.

A comparison of European azhdarchid pterosaurs.

Picture Credit: Everything Dinosaur

Mistralazhdarcho is estimated to be intermediate in size between the medium-sized genus Eurazhdarcho (wingspan of 3 metres) and the enormous Hatzegopteryx (estimated wingspan of 10 metres or more), the two other azhdarchids associated with the island ecosystem of the latest Cretaceous European archipelago.  The different sized pterosaurs might reflect a form of niche partitioning, whereby, different sized animals did not directly compete with each other for resources.

The flying reptile’s genus name is from the “mistral”, a strong, north-westerly wind associated with southern France.  The species name honours the former mayor of Velaux, Jean-Pierre Maggi, without whom, the excavation of the fossil material would not have been possible.

Field Team Members Working at the Velaux Excavation Site

Looking for pterosaur fossils (south-eastern France).

Fossil excavation work at one of the dig sites at Velaux (south-eastern France).

Picture Credit: Royal Belgian Institute of Natural Sciences

The scientific paper: “Mistralazhdarcho maggii, gen. et sp. nov., a New Azhdarchid Pterosaur from the Upper Cretaceous of south-eastern France” by Romain Vullo, Géraldine Garcia, Pascal Godefroit, Aude Cincotta and Xavier Valentin published in the Journal of Vertebrate Paleontology.

29 10, 2018

A Second Mamenchisaurid Dinosaur from Anhui Province is Described

By | October 29th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Anhuilong diboensis – From the Middle Jurassic of Anhui Province

Chinese scientists have published details of a new species of long-necked dinosaur from eastern China.  The fossilised remains, although fragmentary, have permitted the researchers to confidently assign the specimen (AGB 5822), to the Mamenchisauridae family of Sauropods.  The dinosaur has been named Anhuilong diboensis and it suggests that by the Middle Jurassic, mamenchisaurids were already a diverse family.  It is likely that the sandstones and mudstones that form the majority of the fossil bearing, Middle Jurassic-aged strata near Huangshan (Anhui Province), will yield more dinosaur fossils.

A Life Reconstruction of a Typical Mamenchisaurid Dinosaur

Old Long-neck takes a walk

A typical member of the Mamenchisauridae family (Mamenchisaurus).

Picture Credit: Julius Csotonyi/Natural History Museum of Los Angeles County

The Second Member of the Mamenchisauridae from Anhui Province

The fossil material, consisting of the remains of a single forelimb, representing one individual dinosaur (humerus, ulna and radius bones), was distinct enough to permit the scientists, which included researchers from the Chinese Academy of Sciences and the Anhui Geological Museum, to establish a new genus.  Anhuilong diboensis is the second mamenchisaurid to be identified from the Middle Jurassic Hongqin Formation of Shexian, Huangshan (Anhui Province, eastern China).  The first mamenchisaurid from this locality, Huangshanlong anhuiensis, was named and described in 2014.  The authors of the scientific paper describing A. diboensis were also responsible for the earlier study of H. anhuiensis.  A phylogenetic analysis of the limb bones from these two specimens suggest that Anhuilong is the sister taxon of Huangshanlong and with Omeisaurus from Sichuan Province, they together form a sister clade to all other members of Mamenchisauridae.

Views of the Right Humerus of Huangshanlong anhuiensis

Various views of the humerus of the mamenchisaurid Huangshanlong anhuiensis.

Huangshanlong anhuiensis – views of the humerus of a typical mamenchisaurid dinosaur.

Picture Credit: Vertebrata PalAsiatica/Jian-Dong Huang et al

The picture above shows various views of the right humerus (upper arm bone) of H. anhuiensis.  The morphology of limb bones and how they compare to each other (total length of the ulna to the humerus and the total length of the radius to the humerus), are distinct enough for palaeontologists to ascribe them to the Mamenchisauridae and to erect a new genus.

Key

A = humerus viewed from the front.

B = humerus viewed from one side (medial view).

C = humerus viewed from the back.

D = humerus viewed from the other side (lateral view).

E = viewed from the top down (cranial margin pointing upwards)

F = view of a cross section, near the narrowest part of the bone.

G = viewed from underneath (distal view).

The Spread of the Sauropoda

Until recently, palaeontologists had thought that although the Sauropoda were geographically widespread by the Middle Jurassic, sub-groups such as the Mamenchisauridae family and the Diplodocidae had restricted geographical ranges.  However, earlier this year, a diplodocid dinosaur was described from northern China, proving that these long-necked dinosaurs were present in Asia during the Middle Jurassic.  The fossil record for the Mamenchisauridae indicates that these types of Sauropods were restricted to China.

To read the article describing the diplodocid dinosaur (Lingwulong shenqi) from northern China: The First Diplodocid Dinosaur Described from China and the Earliest Known Member of the Diplodocidae

28 10, 2018

A New Species of Archaeopteryx

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Archaeopteryx albersdoerferi – A New Species of Archaeopteryx is Named

Those very rare Archaeopteryx specimens that have been found in the fine-grained, Upper Jurassic deposits of Germany are some of the most intensely researched fossils on our planet.  However, they can still surprise and it seems that we have much to learn about “Urvogel” as the Germans refer to this iconic transitional form between a dinosaur and a true bird.  Writing in the academic journal “Historical Biology”, a team of international researchers have subjected one particular fossil (specimen number eight), to the powerful X-rays of synchrotron microtomography and discovered that this example of the “first bird” is so different from other Archaeopteryx fossils that it merits being categorised as a separate species.

A Life Reconstruction of the Newly Described Archaeopteryx Species (A. albersdoerferi)

Archaeopteryx albersdoerferi life reconstruction.

A life reconstruction of the newly described Archaeopteryx species (A. albersdoerferi).

Picture Credit: Zhao Chuang (supervised by lead author of the scientific paper Martin Kundrát of Uppsala University)

Closer to True Birds in Evolutionary Terms

The scientists, which included researchers from Uppsala University, the Chinese Academy of Geological Sciences and Manchester University’s John Nudds (School of Earth and Environmental Sciences), carried out a three-dimensional analysis of the fossil using the European Synchrotron Radiation Facility (ESRF), located in Grenoble.  The team found that specimen eight is closer to modern birds in evolutionary terms when compared to the other known Archaeopteryx specimens.

Dr Nudds explained:

“By digitally dissecting the fossil we found that this specimen differed from all of the others.  It possessed skeletal adaptations which would have resulted in much more efficient flight.  In a nutshell, we have discovered what Archaeopteryx lithographica evolved into – i.e. a more advanced bird, better adapted to flying – and we have described this as a new species of Archaeopteryx.”

Dr John Nudds with the Archaeopteryx Specimen at the Synchrotron Facility

Dr John Nudds holding an Archaeopteryx fossil specimen.

Dr John Nudds (Manchester University) holding the Archaeopteryx specimen at the European Synchrotron facility (Grenoble, France).

Picture Credit: Manchester University

Differences in the Skeleton – Better Adaptations for Powered Flight

The research team identified numerous, subtle skeletal differences between this specimen and the other Archaeopteryx fossil skeletons.  For example, specimen eight has fused cranial bones, a different pectoral girdle and wing elements and a more robust set of carpals and metacarpals (hand bones).  The X-ray scans revealed that this specimen had very light bones, with numerous air sacs in them.  These characteristics are observed more in modern flying (volant), birds and are not found in the older Archaeopteryx lithographica species.  The fossil studied is the so-called Mörnsheim or Daiting specimen, from strata which is around half a million years younger than the rocks associated with the majority of the German Archaeopteryx fossils.  As such, specimen eight is stratigraphically the youngest Bavarian archaeopterygid.

Archaeopteryx albersdoerferi – “The Phantom”

The Mörnsheim or Daiting fossil has had a colourful history.  It was (allegedly), discovered by a private fossil collector in a quarry near the town of Daiting in southern Bavaria, about twenty miles south of the city of Nuremberg (Germany), sometime in the early 1990’s.  It was incorrectly identified as a Pterosaur and this fossil changed hands several times.  Rumours began to circulate amongst the scientific community that there was another Archaeopteryx specimen but it remained elusive, so much so, that the fossil was nick-named “The Phantom”.  A cast of the fossil was briefly put on display at the Naturkundemuseum in Bamberg (Germany) in 1996 and a short report was written a year later, but this specimen remained out of reach and not accessible for study.

All this changed in 2009, when palaeontologist Raimund Albersdörfer of Schnaittach (Bavaria), purchased the specimen from a private collector and secured its scientific heritage by offering it on long-term loan to the Bavarian State Collection of Palaeontology and Geology in Munich, and obligated himself by contract not to sell the specimen to a non-public entity.  The species name honours the contribution made by Raimund Albersdörfer.  This is not the first time that Raimund has made a privately-owned Theropod specimen available to study.  In 2012, he was honoured by having the trivial name of a feathered dinosaur from southern Germany named after him (Sciurumimus albersdoerferi).

Lead author, Dr Martin Kundrát, commented:

“This is the first time that numerous bones and teeth of Archaeopteryx were viewed from all aspects including exposure of their inner structure.  The use of synchrotron microtomography was the only way to study the specimen as it is heavily compressed with many fragmented bones partly or completely hidden in limestone.”

Is The Really a New Species?

Palaeontologists are aware that this part of Germany where the Archaeopteryx fossil material comes from, was once a series of small islands surrounded by a tropical sea.  The strata were laid down over hundreds of thousands of years and it is therefore quite possible that different species of primitive “dino-bird” evolved over this period.  However, the Mörnsheim specimen was examined using computer tomography that provided an extremely detailed assessment of the fossil material.  It is quite possible, that, if other Archaeopteryx specimens were subjected to the same level of scrutiny, then new information about them would be discovered too.

To read an article from 2016, that reports on the discovery of a twelfth Archaeopteryx specimen, a fossil recovered from strata at least 200,000 years older than other Archaeopteryx fossil material: The Oldest Archaeopteryx in Town

The scientific paper: “The First Specimen of Archaeopteryx from the Upper Jurassic Mörnsheim Formation of Germany” by Martin Kundrát, John Nudds, Benjamin P. Kear, Junchang Lü and Per Ahlberg published in Historical Biology.

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

27 10, 2018

Pachycephalosaurus – Was It Carnivorous?

By | October 27th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Theropod-like Front Teeth Identified in a Pachycephalosaur

Pachycephalosaurus, that dome-headed dinosaur that lived alongside such famous prehistoric animals as T. rex and Triceratops, in the Late Cretaceous of Montana, has always been a bit-player when it comes to depicting life in the very last couple of million years before the extinction of the non-avian dinosaurs.  Its more illustrious contemporaries tend to hog the limelight somewhat.  However, the scientific description of a nearly complete skull and jaws of what has been identified as a juvenile Pachycephalosaurus, might just have revealed a surprising side to this peaceful plant-eater.  The teeth in the front of jaws are triangular and pointed, reminiscent of the dentition of a meat-eating dinosaur.  Could palaeontologists have got Pachycephalosaurus wrong?

A Reconstruction of the Juvenile Pachycephalosaurus Skull and Jaws

Reconstruction of a Juvenile Pachycephalosaurus skull.

A reconstruction of the fossil skull of the juvenile Pachycephalosaurus that has Theropod-like teeth in the front of the jaws.

Picture Credit: Brian Boyle (Royal Ontario Museum)

Front Portion of the Jaws Suggests Omnivory in Certain Pachycephalosaurs

In a presentation made at the annual meeting of the Society of Vertebrate Palaeontology held in Albuquerque, New Mexico, Mark Goodwin (University of California Museum of Palaeontology) and David Evans (Royal Ontario Museum), described a near complete juvenile Pachycephalosaur skull from eastern Montana.  The back of the jaws contained the broad, leaf-shaped teeth which seem well suited to herbivory.  It had been assumed that the teeth in the front of the jaws (premaxilla and the anterior portion of the dentary, immediately behind the predentary), were the same shape.  However, until this fossil specimen was found, no record of the front teeth of these dinosaurs existed.  Palaeontologists may have to re-think their views on the diet of this member of the Hell Creek Formation biota.  The sharp, blade-like triangular teeth located at the front of the mouth seem adapted to ripping and tearing flesh.

The Teeth at the Front of the Jaws are Typical of a Meat-eating Theropod Dinosaur

Pachycephalosaurus Theropod-like teeth.

A close-up view of the teeth in the premaxilla (upper jaw) and the anterior portion of the dentary (lower jaw). Triangular Theropod-like teeth have been identified in a juvenile Pachycephalosaurus.

Picture Credit: Brian Boyle (Royal Ontario Museum) with additional annotation by Everything Dinosaur

Confusing Pachycephalosaurs

Pachycephalosaurus is the largest member of the Pachycephalosauridae family to have been scientifically described and notwithstanding a cameo appearance of a jail-breaking Stygimoloch in the recent “Jurassic World – Fallen Kingdom” movie, perhaps the most famous.  However, not a great deal is known about Pachycephalosaurus and other bone-headed dinosaurs.  Fossil remains tend to be very fragmentary and most species have been named from quite scrappy remains and then you have those amazing skulls to consider.

The CollectA Pachycephalosaurus Dinosaur Model

CollectA Pachycephalosaurus model.

A lithe Pachycephalosaurus dinosaur model.  Pachycephalosaurus (P. wyomingensis) is the largest known member of the Pachycephalosauridae with an estimated body length of 4.6 metres.

Picture Credit: Everything Dinosaur

Several species have been named based on the shape and cranial ornamentation associated with those thickened skulls.  The thick bone may resist erosion and provide palaeontologists with some fossil bone to study, but it has been suggested that the skulls of these dinosaurs changed dramatically as the animal grew.  So much so in fact, that a number of academics, including Mark Goodwin, have published scientific papers that cast doubt on the validity of many Pachycephalosaur species.  For example, palaeontologists such as Goodwin have put forward evidence to suggest that both Dracorex and Stygimoloch are not distinctive species, the fossils ascribed to these two genera could represent juvenile Pachycephalosaurus specimens.

It seems, just like many other types of Late Cretaceous Ornithischian dinosaur, the Pachycephalosaurs underwent extreme changes to the shape of their heads as they grew up.  Such changes in cranial morphology have resulted in the establishment of several species that may actually just represent examples of the same species but at different growth stages.

Some Palaeontologists Suggest that Radical Changes in Skull Shape and Ornamentation Do Not Indicate Different Species but Different Growth Stages

Different skull shapes and ornamentation linked to different growth stages.

It has been proposed that the cranial ornamentation and skull shape of Pachycephalosaurs changed as these animals grew and matured. This can cause confusion when trying to identify species.

Picture Credit: Kari Scannella with additional annotation by Everything Dinosaur

To complicate matters, Pachycephalosaur fossil material covers a period of approximately 2 million years.  Over this timescale, these animals evolved and their skull morphology changed, thus, further blurring the lines between different species and fossils of the same species but at different levels of maturation.

Confirming the Likely Diet of Pachycephalosaurus

It would be difficult to confirm that Pachycephalosaurus also ate other animals as well as plants, but not impossible.  Only one jaw fossil with the front teeth in situ has been found, so scientists don’t know whether the diets of these dinosaurs changed as they grew.  Perhaps, young Pachycephalosaurs were omnivorous, whilst when fully grown, adults tended to consume plants rather than other animals.  The rib cages of those genera which have a more complete fossil record, suggest that these bipeds had large guts, this would indicate a digestive system adapted to processing vegetation.  Professor Philip Currie (University of Alberta), who also attended the Society of Vertebrate Palaeontology meeting, has proposed that studying carbon isotopes preserved in the tooth enamel might provide further evidence relating to diet.  In addition, the many hundreds of examples of isolated, broken teeth from the Hell Creek Formation could be re-examined and checked for any potential affinities with the Pachycephalosauridae.  Feeding traces from fossil bone could also yield more data in support of the idea that bone-headed dinosaurs ate meat.

A Reconstruction of the Skull of an Adult Pachycephalosaurus

A replica skull of Pachycephalosaurus wyomingensis.

Pachycephalosaurus wyomingensis replica skull.

Picture Credit: Everything Dinosaur

A spokesperson from Everything Dinosaur commented:

“It is likely that there are many more examples of Pachycephalosaurs to be found in Upper Cretaceous rocks, hopefully, if more fossil material can be discovered, then palaeontologists will be able to piece together a more complete phylogeny of these strange dinosaurs.  Furthermore, if more examples of their dentition [teeth] come to light, then we might be able to gain a better understanding of their diets. “

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