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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.

7 01, 2020

Turning a Stegosaur Fossil into the “Rosetta Stone”

By | January 7th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Newly Described Specimen of Miragaia longicollum helps to Decipher the Dacentrurinae

A fossil of a stegosaur discovered in 1959 on the coast of western Portugal has helped to decipher the taxonomic relationships of an obscure sub-family of armoured dinosaurs known from the Late Jurassic.  The specimen number MG 4863 has been identified as an example of Miragaia longicollum, a stegosaur named and described in 2009 from fossils found some 6 miles (10 kilometres) further inland.

MG 4863 has been described as a “Rosetta Stone” specimen, just as the discovery of the Rosetta Stone was vital in helping scholars to interpret and understand ancient Egyptian hieroglyphics, these fossils, that had languished in storage for sixty years, can help palaeontologists to distinguish between different genera of closely related stegosaurs.

Laid Out in an Approximate Skeletal Reconstruction (MG 4863) – Newly Described Miragaia longicollum Specimen

Views of the Miragaia longicollum specimen ( MG 4863)

Miragaia longicollum specimen (A) before preparation and (B) after preparation. Material is laid out in approximate articulation.

Picture Credit: Costa and Mateus published in PLOS One

The picture (above), shows the fossil material associated with MG 4863 prior to preparation (September 2015) and after preparation (May 2017).  The fossils have been positioned in an approximate skeletal layout, the box in (B) contains unidentified fossil fragments.

Although far from complete and lacking any evidence of a skull, these fossils, that had been stored in an unprepared state at the Alfragide campus of LNEG (Laboratório Nacional de Energia e Geologia, Portugal), consist of bones that were not part of the original holotype specimen for M. longicollum (specimen number ML 433).  Thus, palaeontologists have more parts of the skeleton of Miragaia longicollum to study and this newly described specimen has helped to decipher the differences between Miragaia and the closely related Dacentrurus.

The Dacentrurinae Deciphered

The first armoured dinosaur to be scientifically described was Dacentrurus armatus (although it was originally named Omosaurus armatus by the famous English palaeontologist Richard Owen).  It was named from a jumbled up set of bones preserved in a block discovered in a clay quarry in Wiltshire (southern England).  The fossilised bones mostly represent the back-end (posterior) portions of an armoured dinosaur.  For a considerable period, stegosaur fossils from strata approximately the same age from the Iberian peninsula were referred to as Dacentrurus.  When ML 433 was excavated all that changed and this part of Europe had its very own stegosaur Miragaia longicollum.  However, the holotype (ML 433), represented the front end (anterior) of the animal, so direct comparisons between Dacentrurus and Miragaia were not possible.

Now that palaeontologists have more fossils of Miragaia to study, thanks to the Alfragide campus specimen, clear differences between these two taxa can be identified, which reinforces their validity.  In addition, ML 4863 is the the most complete dinosaur described from Portugal and the most complete stegosaur described from the whole of Europe.

Comparing the Holotypes of Dacentrurus armatus and Miragaia longicollum with the Newly Described Miragaia Material (ML 4863)

Dacentrurus and Miragaia compared.

Comparing Dacentrurus with Miragaia.  Known fossil bones are shown in white.

Picture Credit: Costa, Mateus et al published in PLOS One with additional annotation by Everything Dinosaur

Both the Miragaia holotype (ML 433) and this newly described specimen (MG 4863), are associated with the Upper Jurassic Lourinhã Formation.  Writing in the on-line academic journal PLOS One, the researchers (Francisco Costa and Octávio Mateus), provide a revised diagnosis for both M. longicollum and D. armatus.

A Land Bridge Between Iberia and North America – Late Jurassic Faunal Interchange

Significantly, the scientists conclude that Miragaia was closely related to a Late Jurassic stegosaur named Alcovasaurus longispinus, which is known from hip bones and other fragmentary fossils associated with a Morrison Formation outcrop in Natrona County (Wyoming, USA).  Not only does MG 4863 help to describe and define two European stegosaurs but it lends weight to the idea that there was an ephemeral land bridge between North America and Iberia that allowed faunal exchange.

A Scale Drawing of Miragaia longicollum

Scale Drawing of Miragaia

“Long-neck from Miragaia”.  A scale drawing of M. longicollum.

Picture Credit: Everything Dinosaur

We have two species of the carnivorous Late Jurassic dinosaur Torvosaurus identified, one from the western United States (T. tanneri) and one from Portugal (T. gurneyi) and now the idea of there being links between the Iberian landmass and North America is reinforced by the conclusion that Miragaia from Portugal and Alcovasaurus from Wyoming were closely related.  Indeed, Alcovasaurus is so similar to Miragaia that the researchers propose that it should be assigned to the same genus and renamed Miragaia longispinus.

To read Everything Dinosaur’s article from 2009 about the discovery of Miragaia longicollumA New Long-necked Stegosaur from Portugal.

4 01, 2020

A New “Thunder Lizard” Tralkasaurus

By | January 4th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

A New Abelisaurid (Tralkasaurus cuyi) from Argentina

A team of scientists based in Argentina have described a new species of abelisaurid from the Huincul Formation in northern Patagonia.  The new dinosaur is represented by a fragmentary skeleton consisting of caudal vertebrae (tail bones), a bone from the upper jaw (maxilla), a distorted pelvic girdle and sacral vertebrae.  Although the fossils were found in a disarticulated state and quite widely scattered, it is likely that the bones represent a single, individual animal.  With an estimated body length of around five metres and a hip height of approximately 1.5 metres, this newest member of the Abelisauridae, named Tralkasaurus cuyi, is much smaller than abelisaurs such as Carnotaurus sastrei, Abelisaurus comahuensis and Ekrixinatosaurus novasi. 

Writing in the “Journal of South American Earth Sciences”, the researchers, which included Mauricio Cerroni, a PhD student at the Museo Argentino de Ciencias Naturales, Buenos Aires (Argentina), conclude that Tralkasaurus probably occupied a different ecological niche compared to the much larger and heavier Late Cretaceous abelisaurids.

A Size Comparison Between Carnotaurus sastrei and Tralkasaurus cuyi

Tralkasaurus cuyi and Carnotaurus sastrei size comparison.

A size comparison between Tralkasaurus cuyi and Carnotaurus sastrei.  Tralkasaurus very probably had a typical abelisaurid body plan, but its size suggests that it was a secondary predator, specialising in hunting other types of prey compared to the much larger carnivorous dinosaurs that it co-existed with.

Picture Credit: Everything Dinosaur

A New “Thunder Lizard”

This new dinosaur was found at the Violante Farm site, in Río Negro province (northern Patagonia).  The sandstones of the Huincul Formation has yielded a diverse range of theropods including the giant carcharodontosaurid Mapusaurus (M. roseae), which is estimated to have measured around 12 metres in length along with the at least 6-metre-long Gualicho (G. shinyae), tentatively described as a member of the Neovenatoridae family and two other abelisaurids Skorpiovenator (S. bustingorryi) and Ilokelesia (I. aguadagrandensis).

The genus name translates as “thunder lizard”, in the native Mapuche language.

Life Reconstruction with Scale Tralkasaurus cuyi

Tralkasaurus scale drawing.

Tralkasaurus cuyi scale drawing.

Picture Credit: Everything Dinosaur

Being much smaller than other abelisaurids such as Abelisaurus and Carnotaurus suggests that this new taxon probably occupied a different ecological niche within the ecosystem.

The scientific paper: “A new abelisaurid from the Huincul Formation (Cenomanian-Turonian; Upper Cretaceous) of Río Negro province, Argentina” by M. A. Cerroni, M. J. Motta, F. L. Agnolína, A. M. Aranciaga Rolando, F. Brissón Egli and F. E. Novas published in the Journal of South American Earth Sciences.

29 12, 2019

Carboniferous Parental Care

By | December 29th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Carboniferous Fossil Provides Evidence of Parental Care

Parental care is a common behaviour amongst mammals, the chances of the offspring surviving are enhanced by the parents making an investment in looking after their young, but when did this behavioural strategy evolve in the ancestors of the Mammalia?  This is a tricky question to answer as evidence for such behaviours is rarely preserved in the fossil record, but a remarkable discovery inside a lithified tree stump dating from around 305 million years ago from Cape Breton Island, Nova Scotia (Canada), may have provided palaeontologists with a fresh insight into prehistoric parenting.

A team of scientists writing in the academic journal “Nature Ecology & Evolution” report the discovery of fossilised remains of an adult lizard-like creature in association with a very young member of the same species preserved within the tree stump.  Finding an adult and associated conspecific juvenile has been interpreted as evidence of the parent staying close to its offspring and therefore a demonstration of parental care.

The creatures are members of the Varanopidae family, so called as these creatures resemble extant monitor lizards (Varanus), but they are not closely related to monitor lizards and are a new genus.  They have been named Dendromaia unamakiensis and if this is prehistoric parental care, then it predates the previous earliest evidence by some forty million years.

Evidence of Parental Care in a Synapsid (Dendromaia unamakiensis)

Dendromaia unamakiensis life reconstruction - evidence of parental care in a synapsid.

Dendromaia unamakiensis life reconstruction.

Picture Credit: Henry Sharpe

A Varanopid (Synapsid) Caring for its Young

The Varanopidae are geographically widespread and temporally diverse.  Most of these animals were around 1 metre in length, much of their body length was made up of their long tails.   They evolved during the Carboniferous and persisted into the Middle Permian.  Varanopids are regarded as one of the most successful of the early types of amniotes, however, whether they are ancestral to modern mammals and members of the Synapsida or whether they are actually diapsids is an area of debate amongst palaeontologists.

Commenting on the significance of the fossil discovery, lead author of the scientific paper Professor Hillary Maddin (Carleton University, Ottawa, Canada), commented:

“Parental care is a behavioural strategy where parents make an investment or divert resources from themselves to increase the health and chances of survival for their offspring.  While there are a variety of parental care strategies, prolonged postnatal care is amongst the most costly to a parent.  This form of parental care is particularly common in mammals, as all mammalian offspring demand nourishment from their mothers.”

The Slab and Counter Slab with the Preserved Remains of the D. unamakiensis Fossils

Dendromaia unamakiensis slab and counter slab.

The slab and the counter slab with the preserved Dendromaia unamakiensis fossils.

Picture Credit: Maddin et al

The researchers concluded that this was evidence of parental care as the preservation of delicate details and structures in the fossils indicate a rapid burial with little movement after death.  The adult and the juvenile were close to each other at the time that they died.  The location of the young animal beneath the hindlimb and encircled tail of the adult resembles a position associated with animals living in a den.

Earliest Evidence of Prolonged Parental Care

The fossils could represent the earliest known record of prolonged parental care.  Prior to this discovery, the previous earliest record of this sort of parental behaviour was identified in a varanopid from the Middle Permian of South Africa.  A scientific paper was published in 2007, describing the discovery of five articulated conspecific varanopid specimens, one of which was much larger than the others.  This was interpreted as an adult and four juveniles, a family group with the older animal looking after its offspring.

Whether Dendromaia is a synapsid of diapsid might be debatable, but whatever the taxonomic relationship to other more advanced amniotes, this fossil discovery suggests that parental care is deeply rooted within the Amniota clade and that parenting behaviour might have been more widespread amongst Palaeozoic tetrapods than previously thought.

The scientific paper: “Varanopid from the Carboniferous of Nova Scotia reveals evidence of parental care in amniotes” by Hillary C. Maddin, Arjan Mann and Brian Hebert published in the journal Nature Ecology & Evolution.

28 12, 2019

Everything Dinosaur’s Top Ten Blog Posts of 2019 (Part 2)

By | December 28th, 2019|Adobe CS5, Animal News Stories, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Everything Dinosaur’s Top Ten Blog Posts of 2019 (Part 2)

Today, we conclude our review of the top ten blog posts written by Everything Dinosaur team members in 2019.  We have produced a blog post for every day of the year and as a result we have covered a tremendous range of topics from new fossil discoveries, highlighting research, the introduction (and retirement) of prehistoric animal replicas, book reviews, artwork created by academic illustrators and scientific discoveries.

Here is our countdown of the top five.

5). Ngwevu intloko – New Dinosaur “Hiding in Plain Sight”

Over the summer, Everything Dinosaur published a wide range of articles.  A new bizarre, shovel-mouthed duck-billed dinosaur (Aquilarhinus), was reported and news of a fast-running Triassic theropod from Switzerland (Notatesseraptor) broke.  We had strange prehistoric parrots, an analysis of the cranial capacity of “parrot lizard” Psittacosaurus and herbivorous crocodylomorphs.  However, number five on our list concerns the discovery of a new type of Triassic herbivorous dinosaur that was found in a museum cabinet.

Fossils once thought to represent an unusual specimen of Massosopondylus (M. carinatus) in the collection of the University of Witwatersrand (South Africa), were assigned to their own genus. Student Kimberley Chapelle and colleagues identified a total of twenty-two characteristics that supported the establishment of a brand new dinosaur genus.  The new dinosaur was named Ngwevu intloko, this member of the Sauropodomorpha had been hiding in plain sight within the vertebrate fossil collection of the University for more than three decades.

Views of the Skull of Ngwevu intloko

Views of the skull of N. intloko.

Views of the skull of Ngwevu intloko.

Picture Credit: Kimberley Chapelle/University of Witwatersrand

4). Keresdrakon vilsoni – Toothless Pterosaur from an Ancient Desert Ecosystem

September and thirty days of blog posts covering stiff T. rex skulls and subsequently how the skull of T. rex may have helped it to keep cool, dinosaur model deliveries to hotels, the most complete dinosaur fossil from Japan (Kamuysaurus japonicus) and the Asian origins of Saurornitholestes, but our number four features a newly described species of pterosaur from Brazil.

Researchers, writing in the academic journal “Anais da Academia Brasileira de Ciências”, identified a new species of edentulous flying reptile that co-existed with the pterosaur Caiuajara and may have fed on its young.  Described as part of a non-tapejarid lineage of pterosaurs outside the Tapejaromorpha, Keresdrakon provides a new perspective on the paleoecology of a Cretaceous desert environment.

Keresdrakon Life Reconstruction It Feeds on the Carcase of a Contemporary Dinosaur (Vespersaurus) whilst a Second Keresdrakon is Mobbed by Juvenile Caiuajara

Keresdrakon life reconstruction.

Keresdrakon life reconstruction, feeding on the carcase of a Vespersaurus.

Picture Credit: Maurilio Oliveira

An honourable mention to Cryodraken boreas the first pterosaur to be described which is unique to Canada.

3). A Potential Terrestrial Tetrapod that May Not Have Gone onto Land

In October, Everything Dinosaur team members covered the amazing TetZooCon event in London, the naming of a new, basal carcharodontosaurian theropod from Thailand (Siamraptor suwati) and the reclassification of crocodiles in New Guinea.  A team of researchers, writing in “Nature” put forward an intriguing new hypothesis that some of the first vertebrates that were capable of terrestrial locomotion may have never left the water.  Parmastega aelidae was a sharp-eyed predator that may have ambushed invertebrates that ventured too close to the sea.

With eyes positioned towards the top of their heads, Parmastega was capable of observing life on land and potential prey without leaving the water.

Life in a Late Devonian Coastal Lagoon (Sosnogorsk, Russia)

Parmastega aelidae life reconstruction.

Sosnogorsk lagoon with Parmastega aelidae hunting behaviour.

Picture Credit: Mikhail Shekhanov for the Ukhta Local Museum

2).  Unusual Styracosaurus Skull Might Change the Way New Dinosaurs are Identified

The first fossil evidence of feathered polar dinosaurs, plans to map extra-terrestrial space objects in a bid to prevent Earth impact events, limited edition dinosaur models, a new predatory dinosaur from Brazil – Gnathovorax cabreirai, all featured in October.  A fossil ape from the Miocene of Germany, Poland’s first pliosaur, Rebor Komodo dragons, a new megaraptorid from “Down Under” and the discovery of a Styracosaurus skull that might just turn palaeontology on its head were also discussed.  “Hannah” an asymmetrical Styracosaurus skull named after the pet dog of palaeontologist Scott Persons has cranial imperfections that could alter the way that scientists identify new species of dinosaur.  Whoops, looks like there may have to be another revision of the Centrosaurinae.

Palaeontologist Scott Persons Poses with the Two “Hannahs” in His Life “Hannah” the pet dog and “Hannah” the Styracosaurus

Scott Persons with dog and "Hannah" the Styracosaurus.

Scott Persons with “Hannah” the Styracosaurus and his dog.

Picture Credit: Scott Persons/University of Alberta

1). Asfaltovenator vialidadi – A New Basal Allosauroid from Argentina

Our blog articles this month have covered such varied topics as galloping crocodilians, 7,000 Facebook “likes”, the announcement of new for 2020 Papo prehistoric animal figures, dinosaur teeth replacement, how to distinguish teenage tyrannosaurs and Mimodactylus libanensis, a new toothy pterosaur from the Late Cretaceous of Lebanon.

However, since we started this top ten countdown with a fossil discovery from North America and despite the focus on asymmetrical dinosaurs, we shall conclude with a dinosaur from the opposite end of the Americas.

Asfaltovenator vialidadi from the Cañadón Asfalto Formation (Chubut Province, Patagonia) roamed South America perhaps as early as 170 million years ago.  Its discovery is important, as most Middle Jurassic theropods are only known from quite fragmentary material and this dinosaur, described as a basal allosauroid, has traits linking it to both the allosauroids and the megalosauroids.  The fossils suggest that the Allosauroidea and the Megalosauroidea evolved from a common ancestor.

A Life Reconstruction of the Newly Described Asfaltovenator vialidadi 

Asfaltovenator illustration.

Asfaltovenator life reconstruction.  The theropod dinosaur shows a mix of anatomical characteristics linking the Allosauroidea and the Megalosauroidea.

Picture Credit: Gabriel Lio/Conicet

Team members at Everything Dinosaur look forward to posting up more blog articles that help to work out taxonomic relationships within the Dinosauria and improve our understanding of ancient life still further in the coming months.

27 12, 2019

Everything Dinosaur’s Top Ten Blog Posts 2019 (Part 1)

By | December 27th, 2019|Adobe CS5, Animal News Stories, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Everything Dinosaur’s Top Ten Blog Posts of 2019 (Part 1)

As this year draws to a close, it is time to reflect on all the work put into writing this web log by Everything Dinosaur team members.  It is also an opportunity to look back and reflect on some of the news stories and articles that we have published over the last twelve months.  Today, we start our look at the top ten articles that we have posted, the countdown from ten to number six.  This list has been compiled based on the total number of comments made, emails received requesting  further information, Facebook “likes” and comments, Pinterest shares and so forth.

So, without any further fuss, here is the first part of our top ten news stories for 2019.

10).  Prehistoric Shark Named After Video Game Character

In January, Everything Dinosaur covered a story about the naming of a new species of Late Cretaceous prehistoric shark.  Strange, unusually shaped shark’s teeth had been found preserved in some of the matrix associated with the famous “Sue” T. rex skeleton.  The tiny teeth reminded the research team of the shape of a spaceship from the 1980’s video game Galaga.  This was the inspiration behind the naming of this new species – Galagadon nordquistae.

Life Reconstruction of Galagadon nordquistae

Galagadon nordquistae life reconstruction.

A life reconstruction of the Late Cretaceous shark Galagadon nordquistae.

Picture Credit: Velizar Simeonovski (Field Museum)

9).  Bajadasaurus pronuspinax Rears its Head

Early February saw the announcement of the discovery of a new, bizarre dicraeosaurid from Neuquén Province, Argentina.  A single, cervical vertebra suggests that Bajadasaurus had a series of forward facing defensive spikes on its neck.  A sauropod that carried its own set of Victorian railings around with it.  Although, the fossil material is fragmentary, CollectA were quick of the mark and have created a stunning replica of this Early Cretaceous giant.  Everything Dinosaur expects to have the CollectA Bajadasaurus replica in stock early in 2020.

A Silhouette Showing a Reconstruction of the Neck Vertebrae of Bajadasaurus and the CollectA Bajadasaurus Dinosaur Model

CollectA Bajadasaurus model and an illustration of the strange cervical vertebrae.

The bizarre cervical vertebrae of Bajadasaurus.  In the silhouette illustration known fossil material is shown in white.

Picture Credit: Gallina et al published in Scientific Reports and Everything Dinosaur

8).  The Jurassic Mile

In March, a blog post was published recording the start of a huge collaboration between a number of European and American museums to explore and excavate an extraordinary, fossil-rich deposit located in the Badlands of Wyoming.  The site has been nicknamed the “Jurassic Mile” and these Morrison Formation deposits have already yielded a treasure trove of dinosaur bones, fossil plants and dinosaur trackways.

Everything Dinosaur will be providing more details of the fossil discoveries in blog articles over the coming twelve months, but the site is so vast that it could be decades before all the fossil material has been collected and studied.

Palaeontologist Phil Manning Sitting Next to a Diplodocid Femur from the “Jurassic Mile”

Professor Phil Manning and the diplodocid femur.

Professor Phil Manning (The University of Manchester) poses next to the diplodocid femur.

Picture Credit: Manchester University

7). New Kid on the Block – Homo luzonensis

The discovery of fragmentary fossil remains of a diminutive hominin on the island of Luzon in the Philippines gave the human family tree a jolt in 2019.  The fossil material, dated to around 67,000 years ago, provides the earliest direct evidence of human inhabitation of the Philippines archipelago, but is Homo luzonensis, with its arboreal adaptations the descendant of a primitive African hominin that somehow migrated to south-eastern Asia or a more advanced hominin, perhaps related to Homo erectus that evolved and changed as it adapted to life on a heavily forested tropical island?

Professor Philip Piper – A Co-author of the Scientific Paper Published in April Holding a Cast of a Toe Bone

A cast of the toe bone of Homo luzonensis.

Professor Piper (Australian National University) holding a cast of a toe bone assigned to H. luzonensis.

Picture Credit: Lannon Harley (Australian National University)

6). A Terrifying Trilobite (Redlichia rex)

In the summer, Everything Dinosaur published an article about the largest trilobite to have been discovered in Australia.  A likely predator of other trilobites, this was a thirty-centimetre-long Cambrian terror. It was appropriately named Redlichia rex and was nicknamed “the king of the trilobites”.  The fossil material comes from an exceptional Lagerstätte known as the Emu Bay Shale on Kangaroo Island, South Australia.  Around fifty different species of trilobite have been identified from this location.  Intriguingly, the predatory and potentially cannibalistic Redlichia rex may also have been hunted, preserved coprolite and the injuries recorded on the exoskeleton of specimens hint at a much larger predator lurking in the shallow sea that once covered this part of Australia.

A Fossil Specimen and the New for 2020 CollectA Redlichia rex Trilobite Model

Redlichia rex fossil and model.

A Redlichia rex trilobite fossil and the new for 2020 CollectA model.

Picture Credit: University of Adelaide/Everything Dinosaur

The naming of a new Cambrian predator inspired the model makers at CollectA to create a replica of Redlichia rex, we expect this figure to make its debut on the Everything Dinosaur website around the middle of next year.  Prior to that event in 2020, we must first complete our chronicle of the top blog posts of 2019, we will conclude this feature tomorrow.

26 12, 2019

Dinosaurs Bred Close to the South Pole

By | December 26th, 2019|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Baby Dinosaurs from Australia Indicate Dinosaurs Bred at High Latitudes in the Southern Hemisphere

Evidence has been found of ornithopod dinosaurs breeding at high latitudes in the northern hemisphere but evidence of similar behaviours in the southern hemisphere, dinosaurs nesting within the Antarctic Circle, had been lacking until now.  Writing in the on-line, open access journal “Scientific Reports”, researchers from the University of New England (New South Wales, Australia), in collaboration with colleagues from the Australian Opal Centre (Lightning Ridge, New South Wales), report the discovery of two tiny thigh bones (femora), that suggest that ornithopods did breed in southern polar environments.

An Artist’s Reconstruction of a Nesting Ornithopod with Recently Hatched Young

Dinosaurs Nesting Close to the South Pole.

A life reconstruction of a nesting Australian ornithopod (based on Weewarrasaurus).  The two femora are indistinct and scientists are not able to identify them down to the genus level but since the wallaby-sized ornithopod Weewarrasaurus is known from close by, the reconstruction has been based on this dinosaur.

Picture Credit: James Kuether

Co-author of the scientific paper, Dr Phil Bell (School of Environmental and Rural Science, University of New England) explained:

“We have examples of hatchling-sized dinosaurs from close to the North Pole, but this is the first time we’ve seen this kind of thing anywhere in the southern hemisphere.  It’s the first clue we’ve had about where these animals were breeding and raising their young.”

Dinosaurs Were Able to Tolerate a Range of Climates

The discovery of the two tiny, opalised thigh bones adds to the growing body of evidence that suggests that the Dinosauria, just like their close relatives the birds,  were remarkably climate-tolerant.  They thrived in equatorial, temperate and polar environments.  Fossilised eggshell and the fossilised remains of tiny hatchling hadrosaurids demonstrates that dinosaurs bred at high latitudes in the northern hemisphere and now the discovery to two partial thigh bones from the Griman Creek Formation exposed near Lightning Ridge suggests that non-iguanodontid ornithopods bred beyond sixty degrees south, well inside the Antarctic Circle.

The Two Opalised Fragmentary Dinosaur Thigh Bones (Femora)

The two tiny thigh bones indicate dinosaur nesting within the Antarctic Circle.

Proximal parts of ornithopod femora from the Griman Creek Formation. LRF 0759 (a–d). LRF 3375 (e–i).  Anterior views (a-e); (b,f) medial views; (c,g) posterior views; (d,i) proximal views; (h) lateral view.

Picture Credit: Scientific Reports

The two fragmentary fossil femurs do not preserve any evidence of histology, so, it is not possible to determine the exact age of the animals from these fossils.  However, when this material is compared with neonatal and slightly older, possible yearling specimens known from the geologically slightly older Eumeralla and Wonthaggi formations in Victoria (Australia), it can be deduced that these are the thigh bones of embryonic dinosaurs, ones that were yet to hatch.

The femur is relatively large (although in these tiny dinosaurs, one femur is estimated to have a total length of 4.5 cm, whilst the other is even smaller with an estimated total length of just 3.7 cm), as such, this bone has a better chance of surviving the fossilisation process than most of the other bones in the dinosaur’s body.  Palaeontologists had thought that dinosaurs living at high latitudes were not permanent residents, they migrated into these areas during the period of extended daylight and subsequent copious plant growth, just like herds of caribou in the Arctic Circle do today.  However, the ornithopods, even as fully grown adults were relatively small animals, as such they were probably not capable of migrating vast distances.  Therefore, it is likely that at least some dinosaurs were permanent residents at very high southerly latitudes and as such they bred at these environments.

Palaeogeographic Map of Australia Around 100 Million Years Ago

Palaeogeographic map of South Pole (100 million years ago).

Palaeogeographic map of Australia at the Albian/Cenomanian boundary (circa 100 million years ago) showing the fossil localities discussed in this paper. (1) Lightning Ridge, Griman Creek Formation (Cenomanian); (2) Dinosaur Cove, Eumeralla Formation (Albian); (3) Flat Rocks, Wonthaggi Formation (Aptian).

Picture Credit: Scientific Reports

The image (above) shows the approximate landmass associated with the polar regions around 100 million years ago.  The tiny fossilised thigh bones come from (1) the Lightning Ridge location.  In order to determine the age of these dinosaurs, they were compared with bones representing neonatal and slightly older animals found at locations (2) and (3).

The researchers conclude that these fossils support they hypothesis that some dinosaurs at least were permanent residents in the very southernmost portion of Gondwana.

The scientific paper: “High-latitude neonate and perinate ornithopods from the mid-Cretaceous of south-eastern Australia” by Justin L. Kitchener, Nicolás E. Campione, Elizabeth T. Smith and Phil R. Bell published in Scientific Reports.

22 12, 2019

Dinosaurs from the “End of the World”

By | December 22nd, 2019|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Scientists Map out the Late Cretaceous Biota of the Chorrillo Formation (Patagonia)

Scientists meeting at the end of year conference of the Argentine Museum of Natural Sciences have presented a new paper that provides an insight into the vertebrate biota associated with the Chorrillo Formation in the Province of Santa Cruz (Patagonia, southern Argentina).  Two new dinosaurs have been described, a basal member of the Iguanodontia estimated to have measured around four metres in length and a much bigger dinosaur, a titanosaur that is estimated to have measured around twenty-five metres long.

Numerous fossil fragments representing several individuals have been found indicating that the iguanodont material might represent a small herd of animals that died together.  This dinosaur has been named Isasicursor santacrucensis, whilst the titanosaur has been named Nullotitan glaciaris.

Two New Dinosaurs were Named at the Conference

Nullotitan and Isasicursor life reconstruction.

A life reconstruction of the titanosaur Nullotitan and the basal iguanodontid Isasicursor.

Picture Credit: CONICET

“Los Dinosaurios del fin del Mundo”

All the fossil material examined in the scientific paper, the dinosaur remains, fossilised titanosaur eggshells, fossils associated with other reptiles including a mosasaur, come from an area of approximately 2,000 square metres.  The sequential strata associated with this part of the Chorrillo Formation plot a gradual ingression of the sea eating into a coastal environment.  The dinosaurs are believed to have lived around 70 million years ago (Maastrichtian faunal stage of the Cretaceous).  As these fossils date from near the end of the Age of Dinosaurs and are geographically located in the south of Argentina, the researchers dubbed them as “Los dinosaurios del fin del mundo” – the dinosaurs from the end of the world.

Silhouette Reconstructions of Isasicursor and Nullotitan

Chorrillo Formation dinosaurs.

Silhouettes of Isasicursor santacrucensis (top) and Nullotitan glaciaris (bottom).

Picture Credit: CONICET

An Enormous Femur

Nullotitan fossil material consists of fragmentary elements from the tail (caudal vertebrae), along with a single neck bone (cervical vertebra), portions of the limbs and other scrappy fossil material.  The largest, most complete fossil bone is a humerus (upper arm bone), it measures 114 cm long, but both the distal and proximal ends of an enormous femur (thigh bone) were also recovered from the site.  The femur is estimated to have been around 190 centimetres in length.

The scientists also reported fragments of theropod eggshells as well as evidence of the presence of both large and small members of the Megaraptoridae, although no fossils associated with abelisaurs were found.  Remains of fishes, lizards, turtles and snakes were also identified along with fossil wood and a large number of terrestrial and freshwater snails.  Mammals were present in the ecosystem, two isolated vertebrae belonging to a small mammal were found.  The fossil material representing individual animals might be quite poor and scrappy in nature, but the number of fossil finds has greatly improved our understanding of the biota of the southern tip of Patagonia close to the K-Pg boundary that marks the end of the Cretaceous.

Fossil Material Ascribed to Isasicursor santacrucensis

Isascursor fossils.

The fossil material associated with Isasicursor.

Picture Credit: CONICET

18 12, 2019

Battle of the Early Vertebrates – Jawless Fish Lose Out

By | December 18th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Bite Mark Analysis in Fossils Plots Demise of Jawless Fish

If you want to survive as a marine vertebrate, then become a powerful predator of your weaker contemporaries!  That’s the conclusion in a new scientific report that plots the demise of the jawless fish and the rise to prominence of our own fishy ancestors.  Writing in the academic journal the Proceedings of the Royal Society B (Biology), researchers from Manchester University conclude that a group of armoured jawless fish (heterostracans), may have been driven to extinction as a result of predation from jawed, transitional forms that show adaptations to a more terrestrial lifestyle.

In essence, one group of ancient fish may have been eradicated by a lineage of fish (sarcopterygians), that led eventually to the first land animals.

Plotting the Demise of the Jawless Fish

Research suggests predation by Sarcopterygians could have led to the extinction of the jawless fishes.

New research suggests that predation could have eradicated some types of jawless fish.

Picture Credit: Julio Lacerda/The University of Manchester

Plotting a Changing Pattern of Bite Marks Preserved in the Fossil Record

Palaeontologists from the University’s Department of Earth and Environmental Sciences, examined over 2,800 fossil specimens, ranging over a timespan of some fifty million years (Wenlock series of the Silurian to the Late Devonian – 430 to 370 million years ago).  The research revealed a changing pattern in preserved bite marks on early vertebrates and led to the conclusion that transitional sarcopterygians such as Panderichthys may have played a significant role in the demise of the jawless fishes (the agnathans).

It was a Fish Eat Fish World as Sarcopterygians Probably Played a Role in the Extinction of Most of the Jawless Fish

Tiktaalik fossil (anterior portion).

 Fossil Material (Late Devonian).  Predation by advanced tetrapodomorphs such as Tiktaalik and Panderichthys could have resulted in the demise of most members of the jawless fish Superclass Agnatha.

Picture Credit: University of Chicago/Harvard/Academy of Natural Sciences

Diverse Agnathans

Nearly all the extant vertebrates have jaws, this includes birds, reptiles, mammals, amphibians and most types of fish.  However, in the Silurian things were different.  The jawless fish, the agnathans, were widespread, specious and very diverse.  Towards the end of the Devonian, these types of fish seem to have gone into decline.  Previous theories that examined the faunal turnover from jawless forms to fish with jaws considered climate change, environmental factors, competition and even predation by eurypterids (sea scorpions).  This new study, proposes that it was jawed vertebrate predators that performed the “coup de grâce” on the majority of agnathans.

Scientists Dr Emma Randle and Dr Robert Sansom (University of Manchester), found that the frequency of bite marks increased through time, reaching a peak toward the extinction of most of the Agnatha.  The pathology, interpreted as signs of predation on the fossil specimens studied, included gouges, scratches and puncture marks on the skeletons of heterostracans.  The pattern of these bite marks correlated with the occurrence of jawed vertebrates and as such, those fish that are linked to the evolution of the tetrapods, including ourselves, may have predated upon and contributed to the extinction of most of the jawless fishes.

Commenting on the research, Dr Robert Sansom stated:

 “It is really exciting to be able to find direct evidence of an ecological interaction between fossil organisms from millions of years ago, especially one that helps us construct our own distant evolutionary history.”

Dr Emma Randle, currently a Scientific Associate at Birmingham University added:

“Heterostracan jawless fishes are really interesting as they are some of the first vertebrates to have bone – in the form of an armour-like ‘exoskeleton’.  They thrived for many millions of years and came in a variety of beautiful forms often dominating the environments they were found within.  Ultimately, like other varieties of armoured jawless vertebrates, they became extinct towards the end of the Devonian Period, but leave us a fossil record that helps us reconstruct the early evolutionary history of all vertebrates.”

The Fossilised Remains of a Silurian Agnathan (Ateleaspis)

Agnathan (jawless fish) fossil.

A fossil of a jawless fish (Ateleaspis) from the Silurian.  The typical body plan of a jawless fish, the broad head was protected by an armoured, bony shield.

Picture Credit: Everything Dinosaur

The groups implicated as the main predators were placoderms, heavily armoured jawed vertebrates and sarcopterygians, the lobe finned fish.  The predator most associated with bite marks was Panderichthys, regarded as a key transitional fossil leading to the evolution of the first terrestrial vertebrates.

The scientific paper: “Bite marks and predation of fossil jawless fish during the rise of jawed vertebrates” by Randle E. and Sansom R. published in the Proceedings of the Royal Society B.

17 12, 2019

Ancient Crocodilian Evolved Unique Specialisations Due to its Size

By | December 17th, 2019|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Purussaurus mirandai – Had an Extra Vertebra to Assist Movement

The giant, prehistoric caiman Purussaurus mirandai, known from Miocene-aged deposits of Venezuela, had unique anatomical adaptations to help it move.  New research, published in the on-line journal “eLife” by an international team of scientists led by Dr Torsten Scheyer of the Palaeontological Institute and Museum of Zurich, demonstrate that this three-tonne predator was able to support its huge bulk by having an extra vertebra in its hip region (sacrum) and the shoulder girdle had also become specially adapted to assist terrestrial movement.

Comparing the Anatomy of P. mirandai to an Extant Caiman (C. Yacare)

P. mirandai compared to a living caiman (C. Yacare).

Comparing the anatomy of P. mirandai to a living caiman (C. Yacare).

Picture Credit: JA Chirinos/The Royal Veterinary College

A Swamp Dweller But Capable of Moving Around on Land

The unusual characteristics suggest that although Purussaurus would have been very much at home in rivers and swamps it was also able to move around on land, although not all that quickly, but over rough terrain and a short distance, this 8-metre-long reptile could have threatened to catch a typical member of our own species .  This research links nicely into a study carried out on the locomotion of modern crocodilians undertaken recently by the Royal Veterinary College, a study that Everything Dinosaur intends to report upon in the near future.

It is the only crocodilian to date to have an extra vertebra in its sacrum.  Purussaurus had three sacral vertebrae not the usual two.  This development requires changes to the “Hox genes” that control where certain body parts are formed.  The scientists noticed that some living crocodilians suffer malformations that cause an extra vertebra to be created in their sacrum, so it is evident that the Hox genes that can make these evolutionary changes remain available to crocodilians today.

Commenting on the findings, co-author of the study, Professor John Hutchinson (Royal Veterinary College) stated:

“We didn’t think that Purussaurus moved quickly on land.  Our findings are important because they help show how development can be altered in order to enable biomechanical changes as animals evolve into larger body sizes.”

Selected Forelimb Bones of Purussaurus from the Urumaco Formation of Venezuela

Purussaurus forelimb fossils.

(A) Interpretative reconstruction of the complete body outline of P. mirandai showing the preserved and assembled bones and the lower jaw in tentative live position.  Left shoulder blade (B) in lateral, medial, and posterior view.  Right shoulder blade (c) in medial view.  Right lower shoulder girdle (coracoid) (D) in dorsomedial, ventrolateral, and anterior view.  Note bony armour osteoderms (in upper part of trunk) and ribs (in lower part of trunk) are not in life position.

Picture Credit: The Royal Veterinary College

Lead author of the research, Dr Torsten Scheyer commented:

“We have been extremely lucky to find such a high amount of fossils in the badlands of Venezuela, which allowed the recognition of the unique condition in the hip region of the giant Purussaurus in the first place.  These old bones show us once again that the morphological variation seen in animals that are long extinct extends well beyond that of what is known in living animals, and thereby broadens our knowledge of what animals can do in evolution.”

An Illustration of the Fearsome Crocodilian Purussaurus mirandai 

Purussaurus mirandai illustrated.

Purussaurus mirandai illustrated, scale bar = 50 cm.

Picture Credit: Everything Dinosaur

The scientific paper: “Giant extinct caiman breaks constraint on the axial skeleton of extant crocodylians” by Torsten M Scheyer, John R Hutchinson, Olivier Strauss, Massimo Delfino, Jorge D Carrillo-Briceño, Rodolfo Sánchez and Marcelo R Sánchez-Villagra published in eLife.

14 12, 2019

A New Basal Allosauroid from Argentina

By | December 14th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Asfaltovenator vialidadi – Linking Megalosaurs and Allosaurs

This week has seen the formal publication of a scientific paper announcing the discovery of a new type of meat-eating dinosaur from Chubut Province in the Patagonia of Argentina.  This dinosaur named Asfaltovenator vialidadi shows a range of anatomical characteristics which are similar to both Allosaurs and Megalosaurs and whilst it poses a bit of a phylogenetic puzzle when it comes to classifying tetanuran theropods (stiff tails), it does suggest that the Allosauroidea  and Megalosauroidea have a common ancestor.

A Life Reconstruction of the Newly Described Asfaltovenator vialidadi

Asfaltovenator illustration.

Asfaltovenator life reconstruction.

Picture Credit: Gabriel Lio/Conicet

Predator of Patagonia Around 175 to 170 Million Years Ago

Discovered back in 2002, from lacustrine deposits (sediments from an ancient lakebed), located about a mile north-east of the village of Cerro Cóndor (Patagonia), the fossil material consists of most of the front portion of the skeleton, including a well-preserved skull.  The genus name honours the geological formation from whence it came, the Cañadón Asfalto Formation and the word “venator” from the Latin for hunter.  The trivial epithet honours the Administración de Vialidad Provincial of Chubut and the Dirección Nacional de Vialidad, for their help with field expeditions of the Museo Paleontológico Egidio Feruglio.

Dating the deposits associated with the Cañadón Asfalto Formation has proved difficult.  Isotope analysis using material from volcanic ash layers has yielded varying results, but in the paper published in the academic journal “Scientific Reports”, the age of the strata associated with this fossil find is stated as late Toarcian to Bajocian, indicating that this predatory dinosaur roamed Gondwana around 175 to 170 million years ago.

Views of the Skull and Jaws of Asfaltovenator with Line Drawings

Skull and jaws of Asfaltovenator with accompanyin line drawings.

Cranial anatomy of Asfaltovenator vialidadi, MPEF PV 3440.  (A) composite reconstruction of the skull and lower jaws, based on disarticulated cranial elements.  (B), graphic reconstruction of articulated skull.  (C), braincase in occipital view.  (D,E) posterior end of left mandible in dorsal view; (D) photo; (E) outline drawing.  Note scale bar (A,B and C) is 10 cm, scale bar (D, E) is 5 cm.

Picture Credit: Scientific Reports

The skull is estimated to be around 80 cm in length and the overall body size of Asfaltovenator is estimated at between seven to eight metres in length.

A Tweak to the Tetanurae

Asfaltovenator demonstrates an unusual combination of anatomical characteristics.  Its discovery could have implications for the way in which palaeontologists arrange the family tree of meat-eating dinosaurs.  The Suborder Theropoda, the lizard-hipped, primarily carnivorous dinosaurs, is further divided up into several sub-groups, for example the allosauroids, megalosauroids, ornithomimosaurs, tyrannosauroids, maniraptorans and their close relatives, the birds.  Arguably, the most successful part of the Theropoda was the Tetanurae (stiff tails), a clade that is defined as all theropods more closely related to modern birds than to Ceratosaurus.  It is thought that the Tetanurae diverged from its sister clade, the Ceratosauria, during the Late Triassic.

The discovery of Asfaltovenator is important, as most Middle Jurassic theropods are only known from quite fragmentary material and this dinosaur, described as a basal allosauroid, has traits linking it to both the allosauroids and the megalosauroids.  This suggests that the Allosauroidea and the Megalosauroidea evolved from a common ancestor and that these two parts of the Tetanurae are more closely related to each other than they are to the Coelurosauria, that part of the Tetanurae that gave rise to the tyrannosaurs, ornithomimids, Maniraptora and the birds.

Postcranial Material and a Skeletal Drawing Showing the Known Fossil Material (Asfaltovenator vialidadi)

Skeletal drawing of Asfaltovenator and postcranial fossil material.

Skeletal reconstruction and postcranial anatomy of Asfaltovenator vialidadi.

Picture Credit: Scientific Reports

Scientists hope that more large tetanurans can be found in Middle Jurassic strata, as further discoveries will help to hone Theropoda classification.

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