All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
//February
8 02, 2019

New Species of Late Cretaceous Oviraptorid Named

By | February 8th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Gobiraptor minutus – The Diversity of the Oviraptoridae in the Late Cretaceous

A new species of oviraptorid dinosaur (Oviraptoridae family), has been described by an international team of scientists.  The little dinosaur was probably feathered and it possessed thickened jaws, an adaptation to feeding on hard food items such as seeds, nuts or the shells of bivalves, molluscs and crabs (durophagous).   The fossilised remains of a single, very young individual were found in the Altan Uul area of Ömnögovi Province, Mongolia, in strata from the famous Upper Cretaceous Nemegt Formation.  The new species has been named Gobiraptor minutus and it helps to demonstrate that this part of Asia in the Late Cretaceous was home to diverse variety of oviraptorids, many of which, probably occupied specialist niches within the ecosystem in a bid to minimise competition for resources.

A Life Reconstruction of Gobiraptor minutus

Gobiraptor minutus life reconstruction.

A life reconstruction of Gobiraptor minutus.

Picture Credit: Do Yoon Kim with additional annotation by Everything Dinosaur

Rare for the Altan Uul Area of Southern Mongolia

Oviraptorid fossil specimens are relatively rare in the Altan Uul area of the Gobi Desert, however, within the Upper Cretaceous deposits exposed within the Gobi Desert, some ten oviraptorid taxa have so far been named and described.  Gobiraptor increases the diversity of oviraptorids known from the Nemegt Formation and demonstrates that these types of Theropod dinosaurs were exceptionally abundant in the mesic environment* of that part of the world during the Late Cretaceous.

A mesic environment* – is a term used in ecology to describe an environment with a moderate amount of water.  Much of this part of Asia during the Late Cretaceous may be associated with a dry, arid environment, for example numerous types of other Theropod fossils come from strata that represent almost desert-like conditions.  These fossils are found in the older Barun Goyot Formation which was laid down under more arid conditions.  The rocks in which the fossils of Gobiraptor were found consist mainly of river channel deposits, indicating that the palaeoenvironment changed and the environment became considerably wetter.

Thus, the finding of a new member of the Oviraptoridae family in the Nemegt Formation, which consists mostly of river and lake deposits, confirms that these dinosaurs were extremely well adapted to wet habitats.

Fragmentary Fossils and Skeletal Reconstruction of Gobiraptor minutus

Gobiraptor minutus skeletal reconstruction.

Grey shaded bones indicate known fossil material.  Note scale bar on skeletal drawing – 10 cm.

Picture Credit: PLOS One

Robust and Thickened Jaws Hint at a Dietary Specialism

Gobiraptor minutus, can be differentiated from other members of the Oviraptorosauria clade in having unusually robust and thickened jaws.  This unique mandibular morphology suggests that Gobiraptor was adapted to feeding on hard food items, it used its strong jaws to crush, indicating potential niche partitioning in the palaeoenvironment to reduce competition amongst small Theropods and within the local population of oviraptorids.  Osteological analysis of the femur suggests that the fossil material represents a very young individual.

The phylogenetic analysis carried out by the researchers defines Gobiraptor as a derived oviraptorid closely related to three taxa from the Ganzhou region of southern China, but, ironically, the analysis suggests that it was rather distantly related to other Nemegt oviraptorids which, as the results of recent studies, are also not closely related to each other.

The authors propose that different dietary strategies may explain the wide taxonomic diversity and evolutionary success of this group of dinosaurs in this part of Asia.

Post-cranial Elements of G. minutus

Post-cranial elements of Gobiraptor.

Left femur in caudal view (A) and medial view (B).  Partial right humerous (C) and ilium (D).  (E) left metatarsal I and pedal digit I in medial view.  (F) left pedal digit IV in lateral view.  Scale bar = 5 cm.

Picture Credit: PLOS One

The genus name honours the Gobi Desert, whilst the specific epithet is from the Latin for small, a reflection on the small size of the holotype.

The scientific paper: “A New Baby Oviraptorid Dinosaur (Dinosauria, Theropoda) from the Upper Cretaceous Nemegt Formation of Mongolia” by Sungjin Lee, Yuong-Nam Lee , Anusuya Chinsamy, Junchang Lü, Rinchen Barsbold and Khishigjav Tsogtbaatar published in PLOS One.

7 02, 2019

Defensive Dicraeosaurids – Forward Facing Spikes Deter Predators

By | February 7th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Bajadasaurus pronuspinax – Sauropod Defences

A newly described Sauropod from northern Patagonia (Argentina), has provided palaeontologists with evidence to help explain why some of these long-necked dinosaurs evolved long, paired spines on the necks.  These features may have had a primary role as defensive structures helping to deter attacks from Theropod predators.  The dinosaur has been named Bajadasaurus pronuspinax and it has been assigned to the Dicraeosauridae family, a sister family to the Diplodocidae within the Sauropoda.  Dicraeosaurids are characterised by having relatively shorter necks and distinctive vertebrae which had long, paired neural spines.  The function of these spines has long been debated.  They have been interpreted as playing a role in visual communication, sexual display and thermoregulation, however, this newly described dinosaur suggests that within this family of long-necked dinosaurs they evolved as a form of defence.

Illustrating Bajadasaurus pronuspinax and the Fossil Find Location

Bajadasaurus skeletal reconstrution and fossil find location.

A skeletal reconstruction of Bajadasaurus, location map of fossil finds and drawing of the fossil material in situ.

Picture Credit: Gallina et al published in Scientific Reports

The image (above), shows a skeletal reconstruction of the head and neck of Bajadasaurus (A), with the preserved fossil material shown in white.  On the right of the image is a location map (B), showing the site of the fossil find, close to the Ezequiel Ramos Mexía lake in Neuquén Province, Argentina.  A line drawing is provided (C), that shows the association and the location of the fossils found at the dig site.

Interpreting Fossils One Cervical Vertebra at a Time

The authors of the scientific paper, propose that the elongated neural spines of this dinosaur always faced forward, presenting a formidable obstacle for any meat-eating dinosaur wanting to attack the animal’s neck.  However, it is worth noting that if the image (above), is studied, the theory of Bajadasaurus having a neck topped with defensive spikes, like some sort of Victorian railings is based on the discovery of a single neck bone, in the skeletal illustration placed in the position of the fifth cervical vertebra.  The appearance of B. pronuspinax is inferred by comparing these fossils to the better-known Amargasaurus (A. cazaui).  Until more fossils are found the appearance of Bajadasaurus and the orientation of those neural spines can only be speculated.

A Model of the Dicraeosaurid Amargasaurus

A model of Amargasaurus.

The Amargasaurus has been mounted onto a bespoke base.  The appearance of Bajadasaurus is based on a comparison with better-known, related dicraeosaurids such as Amargasaurus cazaui.

Picture Credit: Everything Dinosaur

Lead-author of the study, Pablo Gallina and his colleagues, propose that these neural spines may have been covered with keratin and therefore much longer than the spines themselves.  The extent of the neural spines, the length of the keratin sheaths that covered them and the direction they pointed in, remains unknown.  Until more fossils of Bajadasaurus are found, those elongated neural spines remain a mystery.

Naming a New Dinosaur

That one cervical spine forms the basis for the species epithet.  The genus honours Bajada (Spanish for downhill), a reference to the fossil find location – Bajada Colorada.  The species name means “bent over, forward spines”, we shall see if more fossil discoveries reaffirm this interpretation.  Importantly, the fossil material assigned to Bajadasaurus includes much of the skull, thanks to these fossils, the palatal bones, the braincase and a nearly complete left dentary, palaeontologists have a much better idea about the size and morphology of dicraeosaurid dinosaur skulls.

Skull Material Associated with Bajadasaurus pronuspinax and Line Drawing

Bajadasaurus and line drawing.

Skull of Bajadasaurus pronuspinax, specimen number MMCh-PV 75 and line drawing.

Picture Credit: Gallina et al published in Scientific Reports

The skull is quite small for a Sauropod, dicraeosaurids described to date were not as big as some of their diplodocid cousins.  Size estimates range from around 10 to 13 metres in length.  The size of Bajadasaurus is unknown, but based on these fossils, it is likely that this dinosaur was within this size range too.  The orbits are quite large and their position on the top of the skull suggests that when this dinosaur had its head down and it was feeding, it was capable of seeing ahead (forward-directed, stereoscopic vision).

Comparing Bajadasaurus to the Geologically Younger Amargasaurus

The strata of the Bajada Colorada Formation represent sediments laid down at the very beginning of the Cretaceous (Lower Cretaceous, Berriasian/Valanginian faunal stages).  Bajadasaurus roamed Patagonia some 140 million years ago.  Amargasaurus, lived in the same part of South American but around fifteen million years later.  The researchers suggest that the temporal difference between Bajadasaurus and Amargasaurus, supports the idea that the development of an array of defensive spines was likely adaptive over a long time period.  How effective these spines may have been against predators, is once again, open to speculation.  However, the presence of elongated neural spines would have given the impression of a larger animal with a thicker neck.  To a hungry, carnivorous dinosaur the appearance of a bigger more robust adversary may have been enough of a deterrent.

The scientific paper: “A New Long-spined Dinosaur from Patagonia Sheds Light on Sauropod Defence System” by Pablo A. Gallina, Sebastián Apesteguía, Juan I. Canale and Alejandro Haluza published as an open access article in the journal “Scientific Reports”.

6 02, 2019

JurassicCollectables Reviews the Schleich Animantarx

By | February 6th, 2019|Dinosaur Fans, Everything Dinosaur Products, Everything Dinosaur videos, Main Page, Photos of Everything Dinosaur Products, Press Releases, Product Reviews|0 Comments

Schleich Animantarx Model Reviewed by JurassicCollectables

The latest video to be produced by those creative people at JurassicCollectables features one of the new for 2019 Schleich prehistoric animal figures – the Schleich Animantarx.  The Animantarx is described as adorable and as it represents an armoured dinosaur that grew to a length of approximately three metres.  The model works well in scale with JurassicCollectables regular “off-colour Alan”, who makes an appearance towards the end of the review.

The JurassicCollectables Video Review of the Schleich Animantarx Dinosaur Model

Video Credit: JurassicCollectables

An Adorable Animantarx

The narrator describes this model as an “adorable Animantarx” and it certainly has an appeal.  The figure is nicely proportioned and the wet-looking gloss added to the black eyes provides this replica with a certain charm.  It is described as “a cute looking dinosaur” and it is hard to disagree.

The “Adorable Animantarx” Dinosaur Model from Schleich

The Schleich Animantarx dinosaur model.

A close-up view of the Schleich Animantarx dinosaur model.

Picture Credit: JurassicCollectables

Animantarx

The narrator correctly points out that this member of the Nodosauridae family was named and described relatively recently (1999).  It is known from very fragmentary fossils, including a partial skull and a piece of fossilised jaw.  This dinosaur had a distinctive domed skull and tiny horns behind the eyes.  Features that can be seen in the close-up view of the head in the picture above.  It is this attention to detail that elevates this armoured dinosaur model.  Clearly, the Schleich design team have worked hard to produce a model that reflect scientific understanding.   The model may have flaws, but as the narrator points out, there is much to be admired when it comes to examining the dermal armour, the skin tones and the detailing of the body scales.

Measuring the Length of Animantarx

Working out the size of the Schleich Animantarx dinosaur model.

Measuring the Schleich Animantarx dinosaur model.

Picture Credit: JurassicCollectables

Everything Dinosaur team members have also measured this new for 2019 Schleich model.  The figure is approximately fourteen centimetres long.  JurassicCollectables have amassed an extensive library of video reviews about dinosaur models.  The JurassicCollectables YouTube channel is a depository of dinosaur and prehistoric animal themed information.  We suggest you check out their channel and subscribe: Subscribe to JurassicCollectables.

Two Schleich Figures are Compared (Animantarx and Dimetrodon)

The new for 2019 Schleich Dimetrodon is compared with the Schleich Animantarx model.

Comparing the new re-painted Schleich Dimetrodon (right) with the new for 2019 Schleich Animantarx model (left).

Picture Credit: JurassicCollectables

Comparing Schleich Prehistoric Animal Models

One of the great benefits of a JurassicCollectables video review is that it enables viewers to see up close a new figure and to compare it to other recent model introductions.  In this video review, the new for 2019 Schleich Spinosaurus figure is shown and the 2019, re-painted Dimetrodon makes an appearance.  Both the Dimetrodon and the Schleich Spinosaurus have also been recently reviewed on the JurassicCollectables channel.  As mentioned earlier, “off-colour Alan” appears in the video as well.  It is always a pleasure to see “off-colour Alan”.

To view the range of Schleich prehistoric animal models available from Everything Dinosaur: Schleich Prehistoric Animal and Dinosaur Models

5 02, 2019

Iconic Feather Fossil Did Not Belong to Archaeopteryx

By | February 5th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Single Feather Not From Archaeopteryx

One of the most significant fossils to have ever been found, an iconic fossil in vertebrate palaeontology – a single fossilised feather from the Upper Jurassic Solnhofen limestone, is not quite what it seems.  The feather, long thought to be from an Archaeopteryx, is probably not from the “urvogel” at all.  The feather most likely was lost by a dinosaur, before it was blown into a shallow, calm lagoon and preserved as a carbonised film for 150 million years.

The Iconic Single Feather Fossil – Once Synonymous with Archaeopteryx is Not What it Seems

The Berlin feather - preserved as a carbonised film.

The slab from the Berlin museum showing the iconic feather, so long associated with Archaeopteryx but now thought to have belonged to a dinosaur.

Picture Credit: Everything Dinosaur

An international research team which included Dr Michael Pittman (University of Hong Kong), have applied a novel, high-tech, imaging method called Laser-Stimulated Fluorescence (LSF), to  help solve a 150-year-old mystery and to confirm that this feather was not from Archaeopteryx.

Discovered in 1861

The specimen was discovered in 1861 and actually consists of a slab and counter slab component, housed in museums located in Berlin and Munich.  A year later, the fossil feather was formally described and heralded as coming from an Archaeopteryx (A. lithographica), although unlike most feather impressions associated with the dozen or so Archaeopteryx specimens known to science, this feather was preserved as a dark, carbonised film.  This was the first fossil feather ever discovered and at the time fossils of Archaeopteryx were heralded as evidence of a “missing link”, supporting Darwin’s recently published theory of natural selection.

The detailed scientific description published in 1862 commented upon a rather long quill visible on the fossil, but this is unseen today.  Even recent X-ray fluorescence and UV (ultraviolet), imaging studies did not end the controversy of the “missing quill”.  The original existence of this quill has therefore been debated and it was unclear if the single feather represented a primary, secondary, or primary covert feather from Archaeopteryx.

Writing in the academic journal Scientific Reports, the researchers outline their work using the LSF technology and demonstrate its potential for providing new information about extensively studied fossil specimens.  The application of Laser-Stimulated Fluorescence is being developed by Thomas G Kaye of the Foundation for Scientific Advancement, Sierra Vista, Arizona (USA) and Dr Pittman.

Dr Pittman stated:

“My imaging work with Tom Kaye demonstrates that important discoveries remain to be made even in the most iconic and well-studied fossils.”

Detecting the Geochemical Presence of the Lost Quill

The application of LSF technology permitted the scientists, which included lead-author of the study Tom Kaye, to detect the geochemical halo from the rachis, matching the 1862 description.

Views of the Isolated Solnhofen Feather – Not from Archaeopteryx

Images of the Solnhofen isolated feather.

The isolated feather viewed under natural light (top), the original drawing from 1862 by Hermann von Meyer and under (LSF) showing the halo of the missing quill (bottom). Scale bar is 1 cm.

Picture Credit: University of Hong Kong

The shape of the feather has led the researchers to discount the idea that it came from an Archaeopteryx.  Instead, they conclude that it probably came from an unknown species of feathered dinosaur that lived alongside Archaeopteryx in the Solnhofen Archipelago.

Daniela Schwarz, a co-author of the scientific paper based at the Museum für Naturkunde, Berlin, commented:

“It is amazing that this new technique allows us to resolve the 150-year-old mystery of the missing quill.”

This new insight into an iconic fossil specimen also suggests that the diversity of feathered dinosaurs was likely higher in the ancient island archipelago than previously thought.

Tom Kaye added:

“The success of the LSF technique here is sure to lead to more discoveries and applications in other fields.  But, you’ll have to wait and see what we find next!”

4 02, 2019

The New for 2019 Papo Spinosaurus

By | February 4th, 2019|Dinosaur Fans, Everything Dinosaur Products, Main Page, Photos of Everything Dinosaur Products, Press Releases|4 Comments

Everything Dinosaur will be Stocking the New for 2019 Papo Spinosaurus

The new for 2019 Papo Spinosaurus dinosaur model will be available to buy from Everything Dinosaur in the summer of 2019.  This awesome prehistoric animal model was revealed last week by the French manufacturer and this large dinosaur figure has already garnered a great number of positive comments given that it depicts Spinosaurus as a semi-aquatic quadruped, an ecological niche advocated in a ground-breaking scientific paper published on Spinosaurus aegyptiacus back in 2014.  The new Papo Spinosaurus model will be coming into stock in June.

Everything Dinosaur will be Stocking the New for 2019 Papo Spinosaurus Figure

Everything Dinosaur will be stocking the new for 2019 Papo Spinosaurus.

Everything Dinosaur will be stocking the new limited edition Papo Spinosaurus in June 2019.

Picture Credit: Everything Dinosaur

A Secret Papo Project

The Spinosaurus has been kept under wraps by the senior management team at Papo, not even staff members at the company knew about the model’s existence until it was revealed at an exhibition last week.  One of Papo’s best-selling dinosaur models of all time is their original Spinosaurus figure, but this model depicted this Late Cretaceous North African Theropod as a biped, many palaeontologists now believe that Spinosaurus was a specialised piscivore (fish-eater), that moved around on all fours and spent much of its time in rivers and lakes.

The Iconic Papo Spinosaurus Figure – A Dinosaur Depicted as a Biped

Papo Spinosaurus model.

The “classic” Papo Spinosaurus dinosaur model.

Picture Credit: Everything Dinosaur

To read Everything Dinosaur’s blog article that features the 2014 scientific paper that interpreted Spinosaurus as a quadrupedal, semi-aquatic animal: Spinosaurus – “Four Legs are Better than Two Legs”

The New for 2019 Papo Spinosaurus

The new Papo figure, will have limited availability, Papo intend to produce all the models in a single production run, so this new Spinosaurus will be much rarer and more difficult to obtain than the rest of the Papo “les dinosaures” figures.  The Papo Spinosaurus (2019), will also be excluded from the 2019 catalogue, as Everything Dinosaur understands the situation, only a few selected distributors of Papo’s products will be able to gain access to this new replica.

An Exciting New Addition to the Papo Model Range – but with Limited Availability

Spinosaurus dinosaur model from Papo

The awesome Papo Spinosaurus dinosaur model.

Picture Credit: Everything Dinosaur

Reserve List for the Papo Spinosaurus Model

The new for 2019 Papo limited edition Spinosaurus can be reserved at Everything Dinosaur, whilst stocks last.  There is no need to pre-order, there is no deposit or any fees to pay, if you are interested in acquiring this stunning new Spinosaurus when it comes out in June, simply, email Everything Dinosaur: Email Everything Dinosaur to Join our Priority Reserve List

This Reserve List is now Closed

A Close-up View of the Limited Edition Papo Spinosaurus

Papo 2019 Spinosaurus model

Papo 2019 Spinosaurus dinosaur model.

Picture Credit: Everything Dinosaur

To view the range of Papo prehistoric animal models available at Everything Dinosaur: Papo Dinosaurs and Prehistoric Animal Models

The Magnificent Papo Spinosaurus Dinosaur Model (2019)

Papo Spinosaurus (2019).

The new for 2019 Papo Spinosaurus dinosaur model.  The new Papo quadrupedal Spinosaurus has a beautiful sail.

Picture Credit: Everything Dinosaur

This Reserve List is now Closed

3 02, 2019

In Praise of “Carboniferous Giants and Mass Extinction”

By | February 3rd, 2019|Adobe CS5, Book Reviews, Dinosaur and Prehistoric Animal Drawings, Main Page|1 Comment

A Guide to the Late Palaeozoic Ice Age World

Long journeys and hours waiting around in train stations and airport terminals have been made bearable thanks to an excellent book written by George R. McGhee Junior, a Distinguished Professor of Palaeobiology at Rutgers University.  The book is “Carboniferous Giants and Mass Extinction”.  At this time of year, Everything Dinosaur team members seem to have to undertake a lot of travelling, what with their project work and teaching commitments, this eminently informative and enjoyable book has proved a worthy travelling companion.

The Front Cover of “Carboniferous Giants and Mass Extinction”

A new book on the Palaeozoic by George R. McGhee Junior.

“Carboniferous Giants and Mass Extinction” an excellent book that explains the science behind our knowledge of the Carboniferous flora and fauna and explores the impact of the End-Permian mass extinction event.

Picture Credit: Everything Dinosaur/Front Cover Artwork by Richard Bizley

Artwork by Richard Bizley

One of the ironies of having read this book from cover to cover is that we have only just noticed that the front cover artwork showing a typical Late Carboniferous rainforest dominated by lycophyte scale trees, giant horsetails such as Calamites and marattialean tree ferns, was produced by our dear friend Richard Bizley.  Richard is a highly respected artist, he produces exquisite prehistoric scenes as well as landscapes and science fiction illustrations.  The huge millipede in the foreground is Arthropleura armata, which is estimated to have grown in excess of three metres long.  This giant arthropod is illustrated inside the book too, Mary Persis Williams, another highly respected scientific illustrator, shows the scale of A. armata by comparing it to an extant American Alligator (A. mississippiensis).

To read Everything Dinosaur’s review of this beautifully crafted book: Our Review of “Carboniferous Giants and Mass Extinction”

An Insight into an Alien World

Life on Earth in the Carboniferous and Permian was very different from ecosystems today.  As well as the giant arthropods found in terrestrial and marine environments, there were alien-looking plants and bizarre vertebrates some of which (synapsids), were the distant ancestors of mammals.  Top predators in the Carboniferous forests and Early Permian swamps included salamander-like amphibian batrachomorphs such as the monstrous Eryops megacephalus,  which grew to more than two metres in length and was capable of swallowing a small child whole (if humans had lived in the Palaeozoic).

An Illustration of Eryops megacephalus (Scale Drawing)

Eryops megacephalus scale drawing.

A scale drawing of Eryops.

Picture Credit: Mary Persis Williams with additional annotation by Everything Dinosaur

Published by Columbia University Press, “Carboniferous Giants and Mass Extinction” makes a valuable contribution to our understanding of ancient environments and the incredible plants and animals that once inhabited the Earth. It can be found here: Columbia University Press

For more information about the artwork and illustrations of Richard Bizley: Richard Bizley Art

2 02, 2019

A Dinosaur Thesaurus

By | February 2nd, 2019|Dinosaur Fans, Main Page, Photos, Photos of Everything Dinosaur Products|0 Comments

Thesaurus and a Dinosaur

Sorry, we finally gave into temptation and posted up a picture that we had been meaning to share on our various social media platforms for some time.  A dinosaur model posed on a Thesaurus which is was on our reference shelves in our offices, but we could not resist anymore…

A Dinosaur and a Thesaurus

Thesaurus and a dinosaur (Tarbosaurus dinosaur model).

A Tarbosaurus dinosaur model and a Thesaurus.  So sorry, but we couldn’t resist posting up this photograph.

Picture Credit: Everything Dinosaur

A Thesaurus is a reference work that allows you to look up different ways of saying something.  By looking up a word in a Thesaurus a list of synonyms will be provided for that term, other words that have the same meaning or mean something very similar.  For example, the dinosaur in the picture is a bipedal carnivore, if you were to look up the term “carnivorous” in a Thesaurus it would suggest alternative words to use such as zoophagous, meat-eating and creophagous.

CollectA Tarbosaurus

The dinosaur model in the photograph is from the CollectA Prehistoric Life range of figures, it is the CollectA Tarbosaurus.  The picture shows a Tarbosaurus and a Thesaurus together.

1 02, 2019

Pachyrhinosaurus perotorum – New Research is Published

By | February 1st, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Puzzling Pachyrhinosaurs – The Remarkable Pachyrhinosaurus perotorum

Researchers from the Perot Museum of Nature and Science (Dallas, USA), in collaboration with the University of Toronto (Canada), have published an update on their research into one of the most remarkable Late Cretaceous dinosaurs known to science.

Back in 2011, Everything Dinosaur reported that field work in the high Arctic led by palaeontologists from the Perot Museum of Nature and Science had uncovered the fossilised remains of at least ten individual dinosaurs representing a new species of Ceratopsian.  This horned dinosaur, a Pachyrhinosaur, was named Pachyrhinosaurus perotorum and it became the third species to be assigned to this centrosaurine genus.  With numerous specimens to study, the palaeontologists could gain a fresh perspective on how horned dinosaurs changed as they grew up and develop a better understanding of the cranial ornamentation associated with the Ceratopsidae.

The Ontogeny of P. perotorum

Illustrating the ontogeny of a Pachyrhinosaurus (P. perotorum).

How a baby P. perotorum grew up.  With numerous individuals represented at the same dig site, palaeontologists can examine variation within a species and assess how these dinosaurs changed as they matured.

Picture Credit: Perot Museum of Nature and Science

Updating Their Findings

The authors of the original scientific paper describing P. perotorum, Anthony Fiorillo and Ronald Tykoski, have published a new report in conjunction with Kentaro Chiba of the Department of Ecology and Evolutionary Biology at the University of Toronto, updating their research and providing more information on how this species can be distinguished from the two other species of Pachyrhinosaurus.  The continued preparation of fossil specimens collected from the type locality, the  Kikak-Tegoseak Quarry (Prince Creek Formation), has produced more skull elements to study.  The researchers note that their original reconstruction of the type parietal bone was incorrect, the parietal along with the squamosal bone form the neck frill in horned dinosaurs.  The parietal of P. perotorum is similar to the parietal bones of the other species – P. canadensis and P. lakustai.

It is postulated that Pachyrhinosaurus perotorum can be identified by an upturned tip of the rostrum, a dorsally shifted rostral bone lacking a sharply downturned, parrot-like beak and an enlarged median ridge at the posterior end of the nasal boss.  Other differences in cranial morphology are also tentatively proposed in the new scientific paper, published in the Journal of Systematic Palaeontology.

A Speculative Illustration of the High Northern Latitude Ceratopsian Pachyrhinosaurus perotorum

A northern Ceratopsian with a shaggy coat.

A speculative illustration of Pachyrhinosaurus perotorum with a shaggy coat of feathers.  Although northern Alaska was warmer in the Late Cretaceous than today, it would have been distinctly chilly, too cold for ectothermic reptiles and it has been speculated that the dinosaur biota of high latitudes may have been specifically adapted to cold climates.  In this illustration, Pachyrhinosaurus has been depicted with a long, shaggy coat of feathers to help keep out the cold.

Picture Credit: Mark Witton

The Sister Taxon of P. canadensis

A cladistic analysis undertaken by the team using this new dataset in conjunction with previous research confirms that the Pachyrhinosaurus genus is monophyletic (all descended from a common ancestor) and that Pachyrhinosaurus canadensis is the sister taxon to P. perotorum.  In addition, this research supports the idea that parietal and squamosal frill ornamentations alone do not adequately address the variables in craniofacial morphology needed to distinguish between species of Pachyrhinosaurus.

The continuing research into horned dinosaurs that lived at high latitudes is helping palaeontologists to gain a better understanding of a unique ecosystem that existed towards the end of the dinosaur age.  Pachyrhinosaurus perotorum is not only the youngest Pachyrhinosaur species known, it is also the geologically youngest known centrosaurine.  With three species assigned to the genus, Pachyrhinosaurus is the most speciose of all the Centrosaurinae genera.

A spokesperson from Everything Dinosaur commented:

“Pachyrhinosaurus perotorum holds a special place in Ceratopsidae research.  It lived at a higher latitude than any other horned dinosaur known to science and, as a consequence, had to endure some very tough and harsh climatic conditions.  Whether this dinosaur was a seasonal migrant to the area in summer to take advantage of the 24-hours of daylight that permitted abundant plant growth, or whether this reptile was a permanent resident remains uncertain.  However, the discovery of the fossilised remains of a juvenile at the Kikak-Tegoseak Quarry, suggests that this dinosaur could have been indigenous to northern Alaska during the Maastrichtian faunal stage.”

To read Everything Dinosaur’s original article from 2011 that announced the discovery of a third species of Pachyrhinosaurus: A New Species of Pachyrhinosaurus – P. perotorum.

The scientific paper: “New Data and Diagnosis for the Arctic Ceratopsid Dinosaur Pachyrhinosaurus perotorum” by Ronald S. Tykoski, Anthony R. Fiorillo and Kentara Chiba published in the Journal of Systematic Palaeontology.

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