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Articles, features and information which have slightly more scientific content with an emphasis on palaeontology, such as updates on academic papers, published papers etc.

29 05, 2020

Wightia declivirostris – A Terrific Tapejarid Pterosaur

By | May 29th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Jawbone Leads to an Isle of Wight Tapejarid Pterosaur

A single, fragmentary jawbone from the upper jaw of a pterosaur found on the Isle of Wight has demonstrated just how diverse and widespread the Tapejaridae family of pterosaurs were.  The fossil bone, a partial premaxilla from the Lower Cretaceous (Barremian) Wessex Formation of Yaverland (Isle of Wight), represents a new species, the first record of a tapejarid pterosaur from the Wessex Formation and one of the oldest examples of this pterosaur family to have been found outside of China.  The flying reptile has been named Wightia declivirostris.

A Life Reconstruction of Wightia declivirostris (Wessex Formation)

Wightia declivirostris from the Isle of Wight

A life reconstruction of the newly described tapejarid from the Lower Cretaceous of the Isle of Wight (Wightia declivirostris).

Picture Credit: Megan Jacobs (University of Portsmouth)

Terrific Toothless Tapejarids

The terrific toothless tapejarids with their reputation for taking head crest development to the extreme, are known from relatively abundant fossil material associated with the Santana and Crato Formations of Brazil.  In addition, several members of the Tapejaridae family are associated with the Jiufotang Formation of China.  However, fragmentary fossils are known from elsewhere in the world such as Spain (Europejara olcadesorum) and a toothless, rather deep lower jaw tip along with other partial bones from the Kem Kem beds of Morocco suggests that these types of flying reptile may have persisted into the early Late Cretaceous.

Two of the authors associated with this scientific paper, Professor David Martill and Roy Smith (both from the University of Portsmouth), recently published a report on the discovery of a north African tapejarid which was named Afrotapejara zouhrii, one of a spate of recent Moroccan pterosaur discoveries.  To read Everything Dinosaur’s article about this: That Fourth Moroccan Pterosaur.  It seems that these fancy-crested, edentulous flying reptiles were much more geographically and temporally diverse than previously thought.

A Typical Illustration of a Tapejarid Pterosaur (Tupandactylus imperator)

Tupandactylus illustration.

A scale drawing of the tapejarid Pterosaur Tupandactylus imperator.  The Tapejaridae are thought to have all sported flamboyant head crests.

Picture Credit: Everything Dinosaur

The Isle of Wight Pterosaur is More Closely Related to Chinese Tapejarids

Amateur fossil hunter John Winch discovered a pterosaur snout near the cliff at Yaverland Point in Sandown Bay, in a fossil plant debris layer.  The unusual shape and thin bone walls suggested that it was from a pterosaur.  The fragment of jaw, although eroded, demonstrates the characteristic downturned tip, with numerous tiny holes (foramina), on the occulsal surface which indicate the presence of minute sensory organs for detecting food.

The Holotype Material Wightia declivirostris

premaxilla of Wightia declivirostris.

The isolated, partial premaxilla of Wightia declivirostris.

Picture Credit: University of Portsmouth

The jaw fragment was passed to palaeontology student at Portsmouth University, Megan Jacobs, who confirmed it was a rare find and definitely pterosaurian.  Analysis of the specimen suggests that Wightia is more closely related to the older and more primitive tapejarid Sinopterus from Liaoning (Jiufotang Formation), than it is to Brazilian tapejarids.  The genus name of this newly described flying reptile honours the Isle of Wight, whilst the species (trivial) name means “slanting beak”, a reference to the typically tapejarid morphology of the partial premaxilla.

Both the Wealden Formation and the geologically younger Vectis Formation on the Isle of Wight have yielded pterosaur specimens, although they tend to consist of highly fragmentary remains.  The discovery of Wightia declivirostris demonstrates how significant the Lower Cretaceous Isle of Wight sediments are to palaeontologists as they try to plot the radiation of different types of flying reptile during the Early Cretaceous.

The scientific paper: “First tapejarid pterosaur from the Wessex Formation (Wealden Group: Lower Cretaceous, Barremian) of the United Kingdom” by David M. Martill,  Mick Green, Roy E. Smith,  Megan L. Jacobs and John Winch published in the journal Cretaceous Research.

22 05, 2020

13,000 Edmontosaurus Bones and Counting

By | May 22nd, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Massive Edmontosaurus Bonebed Provides Data on Dinosaur Decomposition

A team of scientists have produced a study mapping an astonishing dinosaur bonebed that has so far yielded a staggering total of 13,000 individual fossil elements.  In truth, the bonebed contains many more fossils, but individual dinosaur teeth, ossified tendons and other fragmentary elements under five centimetres in length have not been counted.  The site is located in eastern Wyoming and consists almost entirely of the preserved remains of a single type of dinosaur, a hadrosaur (Edmontosaurus annectens).  The bonebed study has not only provided a great deal of information about this duck-billed dinosaur but shed light on how death assemblages consisting of a large number of corpses are formed and how various bones of differing sizes might be transported before final deposition.

Dinosaur Bonebeds such as the Danek Edmontosaurus regalis Bonebed in Edmonton Have Yielded Thousands of Fossil Bones

Excavating an Edmontosaurus.

The Danek Edmontosaurus bonebed is typical of an Edmontosaurus-dominated bonebed which are widespread in the Upper Cretaceous (Campanian to Maastrichtian) of western North America).

Picture Credit: Victoria Arbour

The Hanson Ranch Bonebed (Lance Formation)

Writing in the on-line, open access journal PLOS One, the scientists which include Keith Synder of the Biology Dept. of the Southern Adventist University, Tennessee, document the taphonomy and depositional history of an extensive E. annectens bonebed known as Hanson Ranch, in the Lance Formation of eastern Wyoming.  The bonebed includes five main quarries and three exploratory quarries.  Approximately 13,000 elements including around 8,400 identifiable bones, have been recovered in 506 square metres of excavated area in twenty years (1996-2016).

Virtually all the fossils are located within a fine-grained (claystone to siltstone) bed that has a maximum depth of two metres.

Mapping the Stratigraphy of the Main Bonebeds at the Hanson Research Station (Wyoming)

The Stratigraphy of the Hanson Research station.

Local stratigraphy associated with the main bonebeds at the Hanson Research station.  The green arrow indicates position of main bonebed.

Picture Credit: Synder et al (PLOS One) with additional annotation by Everything Dinosaur

An Excellent State of Preservation

Almost all the fossils recovered from the site exhibit exquisite preservation with little or no abrasion, breakages or signs of weathering prior to deposition.  All the material is disarticulated and scattered although over a relatively confined area.  This evidence in conjunction with analysis of the sediments associated with the fossils indicates that the bones were moved and buried after a period of initial decay and decomposition of the Edmontosaurus carcasses.

Mapping the Distribution of Fossil Bones in a Bonebed

A map showing the distribution of fossil material in an Edmontosaurus bonebed.

A map showing typical disarticulated fossil bone distribution in a bonebed.

Picture Credit: Synder et al (PLOS One)

Gaining a Better Understanding of Edmontosaurus Biostratigraphy

The thousands of fossil bones represent mainly adult or sub-adult specimens.  Due to the huge number of fossils associated with the Hanson Research site, the scientists have been able to gain a deeper understanding of Edmontosaurus biostratigraphy including how elements from the skeleton can be transported over distances prior to deposition.  The most abundant fossil bones are ischia, pubes, scapulae, ribs and limb bones.  In contrast, vertebrae, ilia and chevrons are rare.

When it comes to cranial material lower jaw bones (dentaries), nasals, quadrates and jugals are prevalent whilst premaxillae (upper jaw bones), predentaries and bones associated with the braincase are seldom found.  The researchers suggest that following decay and break-up of the carcase, water action sorted and removed the articulated sections such as the backbone and the smaller bones such as the digits and toes, before, or at the same time, the remaining material was swept up in a subaqueous debris flow that created the final deposit.

The scientists suggest that similar processes may have been at work that created the other hadrosaurid-dominated Upper Cretaceous bonebeds associated with such geological formations as Hell Creek, Two Medicine, Horseshoe Canyon, Prince Creek as well as the Lance Formations of western North America.  It is noted that there is a remarkably similar skeletal composition among the fossil bonebeds studied.  It is also noted that there is a significant correlation between the hadrosaurid bonebeds and fluvial assemblages representing thanatocoenosis* events seen with modern-day vertebrate death assemblages.

Thanatocoenosis* Explained

Thanatocoenosis refers to a site where a collection of fossils representing a variety of organisms are found together.  Such sites are often referred to as death assemblages.  The organisms represented at the location may not have been associated in life, but their remains have been transported and deposited together thus forming a fossil bed composed of an extensive amount of fossilised material.

Not All of the Dinosaur Fossils are Edmontosaurus

The bonebed can be described as monodominant as the vast majority of the fossil material found can be assigned to just one species Edmontosaurus annectens.  Non-dinosaurian terrestrial taxa identified include mammals and squamates along with the remains of many aquatic creatures such as crocodiles, turtles, gar and other fishes and numerous molluscs.  Some other types of plant-eating dinosaur are represented notably, ceratopsids, pachycephalosaurs, nodosaurs and members of the family Thescelosauridae.  Numerous shed theropod teeth are also associated with this location.  Everything Dinosaur will post up a separate article detailing one rather special theropod fossil associated with a quarry close to the Hanson Research station in the near future.

A Life Reconstruction of the Hadrosaurid Edmontosaurus

Wild Safari Prehistoric World Emontosaurus model.

The new for 2020 Wild Safari Prehistoric World Edmontosaurus dinosaur model.

Picture Credit: Everything Dinosaur

The scientific paper: “Over 13,000 elements from a single bonebed help elucidate disarticulation and transport of an Edmontosaurus thanatocoenosis” by Keith Snyder, Matthew McLain, Jared Wood and Arthur Chadwick published in PLOS One.

20 05, 2020

The First Elaphrosaurine Theropod Reported from Australia

By | May 20th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Curious Cervical Leads to Startling Conclusion

Think of a theropod dinosaur and a ferocious carnivore with a large head and big teeth probably comes to mind.  However, the Theropoda is an extremely diverse clade within the Dinosauria, not all of them were big, particularly ferocious or even had teeth.   One group the elaphrosaurines, were very bizarre indeed and the discovery of a single neck bone in Victoria has led to the conclusion that these strange, light-weight dinosaurs distantly related to Carnotaurus, roamed Australia in the Early Cretaceous.

A Life Reconstruction of the Australian Elaphrosaurine

Life reconstruction of the elaphrosaur from Victoria.

A life reconstruction of the first elaphrosaur from Australia.

Picture Credit: Ruairdh Duncan (Swinburne University of Technology, Victoria)

From the Lower Cretaceous of Australia

Volunteer Jessica Parker discovered a 5-centimetre-long bone whilst helping out at the annual Dinosaur Dreaming excavation near Cape Otway, Victoria (2015).  The sediments at the site, known as Eric the Red West, date from the late Albian faunal stage of the Lower Cretaceous and are part of the Eumeralla Formation.  At first, the bone identified as a cervical vertebra (neck bone), was thought to have come from a pterosaur.

Intriguingly for Swinburne University palaeontologist Dr Stephen Poropat and PhD student Adele Pentland, once the fossil specimen had been prepared it became clear that this was not a bone from the middle portion of the neck of a flying reptile.

Dr Poropat explained:

“Pterosaur neck vertebrae are very distinctive.  In all known pterosaurs, the body of the vertebra has a socket at the head end, and a ball or condyle at the body end.  This vertebra had sockets at both ends, so it could not have been from a pterosaur.”

The Cervical Vertebra – Evidence of Australia’s First Elaphrosaur

The cervical vertebra (elaphrosaur0.

The five-centimetre-long bone identified as a middle cervical from an elaphrosaur.

Picture Credit: Dr Stephen Poropat

Geologically Much Younger Than Most Elaphrosaurines

The taxonomic affinity of the subfamily Elaphrosaurinae within the Theropoda remains controversial.  A number of authors have placed this little-known group, characterised by their small, light, graceful bodies, tiny heads, long necks and reduced forelimbs within the Noasauridae family, which means that they are distantly related to abelisaurids such as Ekrixinatosaurus, Majungasaurus and Carnotaurus.

Most elaphrosaurs are known from the Late Jurassic, but this new elaphrosaur from Australia, lived some forty million years later. Only Huinculsaurus (H. montesi), from the Cenomanian/Turonian (early Late Cretaceous), of Argentina is geologically younger, than the Australian fossil remains.

The Fossil Find Location, Typical Elaphrosaurine Body Plan and Placing the Fossil Find in a Chronological Context

Elaphosaur timeline and typical body plan.

A silhouette of the elaphrosaur with a map showing fossil location and a timeline showing elaphrosaurine chronology.  The newly described elaphrosaurine from Victoria is geologically the second youngest member of this group known.

Picture Credit: Poropat et al (Gondwana Research)

A Dinosaur of the Polar Region

The discovery of this single, fossilised neckbone adds support to the idea that the elaphrosaurines were geographically and temporally much more widespread than previously thought.  The similarity of these dinosaurs to the much better-known ornithomimosaur theropods (bird mimics), could help to explain why few other Cretaceous elaphrosaur specimens have come to light. Fossil material may have been found but misidentified as representing ornithomimids.

As the Cape Otway location would have been situated much further south during the Early Cretaceous (110-107 million years ago), at around a latitude of 76 degrees south, this implies that elaphrosaurines were capable of tolerating near-polar palaeoenvironments.

Recently, Everything Dinosaur wrote a post about the discovery of noasaurid from an opal mine close to Lightning Ridge (New South Wales).  Noasaurids and elaphrosaurines were related, most scientists classifying them as different branches within the Abelisauroidea.  Coincidentally, the New South Wales noasaurid was identified from a single cervical vertebra too.  Both it and the Cape Otway elaphrosaurine dinosaur have not been assigned to any genus, but both fossils are likely to represent new species.

To read Everything Dinosaur’s article about the recently discovered noasaurid from New South Wales: Noasaurids from Australia.

The scientific paper: “First elaphrosaurine theropod dinosaur (Ceratosauria: Noasauridae) from Australia — A cervical vertebra from the Early Cretaceous of Victoria” by Stephen F. Poropat, Adele H. Pentland, Ruairidh J. Duncan, Joseph J. Bevitt, Patricia Vickers-Rich and Thomas H. Rich published in Gondwana Research.

4 05, 2020

Stellasaurus – “Star Lizard”

By | May 4th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Stellasaurus ancellae – Missing Link from the Two Medicine Formation of Montana

A new species of horned dinosaur has been described based on fossil material from the famous Two Medicine Formation of north-western Montana.  The new species named Stellasaurus ancellae is a possible missing link in the evolutionary transition of Centrosaurinae dinosaurs from Styracosaurus to one of the last of the horned dinosaurs known to science – Pachyrhinosaurus.  Stellasaurus means “star lizard”, reflecting the ornate star-shaped head crest and in honour of British rock/pop star David Bowie, famous for his flamboyant appearance and his hit single “Starman” which was released on April 28th 1972, almost 48 years to the day that the Stellasaurus scientific paper was published in Royal Society Open Science.

United by a Flamboyant Appearance David Jones AKA David Bowie and “Star Lizard” AKA Stellasaurus

Two flamboyant characters David Bowie and Stellasaurus.

David Bowie (left) and Stellasaurus ancellae (right).

Picture Credit: Getty Images and Andrey Atuchin

Stellasaurus ancellae

Just like the career of David Bowie, Stellasaurus has had to wait a while before becoming famous.  The fossil material now assigned to Stellasaurus was discovered in 1986, near the town of Cut Bank in Montana, close to the USA/Canadian border.  The discovery was made by Carrie Ancell.  It remained catalogued but not studied in the Museum of the Rockies (Montana), vertebrate fossil collection.  The contribution of Carrie Ancell, now a senior preparator at the Museum of the Rockies, has been recognised as the species name honours her.  Carrie Ancell has played a significant role in developing our understanding of northern Laramidian centrosaurines.  She discovered and prepared MOR 492, the holotype specimen of Stellasaurus ancellae, as well as the holotype of Achelousaurus horneri, and co-discovered the holotype of Einiosaurus procurvicornis.

Views of the Holotype Fossil Material of Stellasaurus ancellae

Holotype fossil material for Stellasaurus ancellae

Left lateral parietal bar of Stellasaurus ancellae holotype MOR 492 in dorsal and ventral views.   The line drawing has been reproduced from a PLOS One article (Evans and Ryan).  Note scale bar on left equals 10 cm.

Picture Credit: Wilson et al/Royal Society Open Science

Reviewing the Centrosaurinae Fossil Material from the Two Medicine Formation

A review of cranial material, specifically the ornamentation associated with the neck frill (parietal processes), previously assigned to the centrosaurine Rubeosaurus ovatus resulted in the identification of this new taxon.  However, this assessment could mark the demise of R. ovatus as the researchers, which include John Wilson of Montana State University, conclude that only what was the holotype fossil, a partial parietal specimen number USNM 11869, can be attributed Rubeosaurus.  This could spell the end for Rubeosaurus.  When USNM 11869 was first described it was assigned to a new species of Styracosaurus (S. ovatus).  Thus, this new paper proposes that the genus Rubeosaurus is now no longer valid and that Styracosaurus ovatus is the sister taxon to Styracosaurus albertensis and Stellasaurus marks a missing link in centrosaurine evolution between Styracosaurus and Einiosaurus procurvicornis.

A Stratigraphical and Temporal Assessment of Late Cretaceous Centrosaurines Based on Two Medicine Formation Fossil Material *

The centrosaurine lineage from Styracosaurus to Pachyrhinosaurus.

Stratigraphic and temporal relationship between Two Medicine Formation centrosaurine taxa. * Pachyrhinosaurus lakustai fossil material is not from the Two Medicine Formation but from the younger unit 4 sediments of the Wapiti Formation of Canada.

Picture Credit: Wilson et al/Royal Society Open Science

A Missing Link Amongst the Centrosaurinae

The researchers postulate that Stellasaurus represents a missing link in the centrosaurine family tree.  The fossils of Stellasaurus are believed to be around 75 million years old.  From a stratigraphical perspective, they are younger than Styracosaurus albertensis fossils, but older than fossils assigned to Einiosaurus.  That flamboyant head shield with its various lumps and bumps could reflect a transitional stage between the headshield morphology of Styracosaurus and that of Einiosaurus.  It is suggested that Stellasaurus was preceded by Styracosaurus and that Styracosaurus evolved into Stellasaurus.  In addition, Einiosaurus evolved from Stellasaurus.

A Transitional Process – One Horned Dinosaur Leading Directly to Another Species of Horned Dinosaur

Anagenesis amongst centrosaurines.

Anagenesis within centrosaurine dinosaurs.  Stellasaurus evolved from Styracosaurus and Einiosaurus evolved from Stellasaurus.

Picture Credit: Everything Dinosaur/Andrey Atuchin

Anagenesis in the Centrosaurinae

Commenting upon the importance of this new research, lead author John Wilson stated:

“The ornamental horns and spiky frills on the skulls of these animals are what changed the most through evolution.  The new species has skull ornamentation which is intermediate.  This gives us evidence these species are members of a single, evolving lineage – this type of evolution is called anagenesis.”

The Phylogeny of the Centrosaurinae from Statistical Analysis Undertaken by the Research Team

Phylogeny of the Centrosaurinae based on Bayesian analysis.

Phylogeny of the Centrosaurinae clade of the Ceratopsidae based on Bayesian statistical analysis mapped against a temporal range.  Styracosaurus ovatus (formerly Rubeosaurus ovatus), is placed as the sister taxon to Styracosaurus albertensis, whilst Stellasaurus is mapped between S. albertensis and Einiosaurus procurvicornis.

Picture Credit: Wilson et al/Royal Society Open Science

The scientific paper: “A new, transitional centrosaurine ceratopsid from the Upper Cretaceous Two Medicine Formation of Montana and the evolution of the ‘Styracosaurus-line’ dinosaurs” by John P. Wilson, Michael J. Ryan and David C. Evans published in Royal Society Open Science.

2 05, 2020

Spinosaurus – The River Monster

By | May 2nd, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Spinosaurus an Aquatic Dinosaur

A team of international researchers including scientists from Leicester University, the University of Portsmouth and the University of Detroit Mercy, have published a paper in the academic journal “Nature” that concludes that the giant theropod Spinosaurus was indeed an aquatic animal.  In the autumn of 2014, a paper was published in the journal “Science” entitled “Semiaquatic adaptations in a giant predatory dinosaur”.  Spinosaurus was depicted as an obligate quadruped very much at home in the water.  In this latest publication, three of the authors involved in the earlier study, Nizar Ibrahim of the University of Detroit Mercy, Cristiano Dal Sasso and Simone Maganuco from the Natural History Museum of Milan (Italy), have collaborated with numerous other researchers in the analysis of Spinosaurus aegyptiacus tail bones.

The tail of Spinosaurus was unlike any other known theropod.  The fossil tail bones, indicate that the tail was wide, flexible and fin-like.  It seems very well adapted to propelling this huge dinosaur through water.  The researchers conclude that this is unambiguous evidence for an aquatic propulsive structure in a member of the Dinosauria.  In other words, Spinosaurus was very much at home in the rivers, swamps and lakes of the Cretaceous of northern Africa.  Here is one dinosaur that took to the water.

A Life Reconstruction of Spinosaurus (S. aegyptiacus) 2020

Swimming Spinosaurus 2020

A pair of spinosaurids hunting the giant, prehistoric sawfish Onchopristis.

Picture Credit: Davide Bonadonna/National Geographic

The beautiful illustration (above), depicts Spinosaurus hunting the 8-metre-long sawfish (Onchopristis).  A partial fossil jaw found in 1975 (MSNM V4047), attributed to Spinosaurus had a vertebra thought to have come from an Onchopristis embedded within it.  Although, the vertebra is thought to have become lodged after the Spinosaurus died, it demonstrated that Spinosaurus and this giant prehistoric fish were contemporaneous.

Not All Dinosaurs were Entirely Terrestrial

Unlike a lot of Kem Kem fossil material from Morocco, the Spinosaurus specimen, which was discovered in 2015, with the tail section found in 2018, consists of numerous associated bones.  Most of the vertebrate fossils found within these deposits are isolated, but these caudal vertebrae with their tall neural spines and elongated chevrons, have permitted the researchers to reconstruct the tail and to test its swimming capabilities using robotic flapping apparatus that was built to model the tail’s morphology and motion.  The researchers conclude that the tail of Spinosaurus was long, strong, flexible and ideal for propelling this monster through water.  It is likely that these fossils will provide much more information on the enigmatic Spinosaurus, as the material represents the most complete theropod dinosaur found to date in northern Africa.

The Reconstructed Spinosaurus – Obligate Quadruped with a Typical Theropod Tail (circa 2014)

Life-size reconstruction and supplemental figure from the autumn 2014 scientific paper.

Picture Credit: Davide Bonadonna (top) Ibrahim et al (bottom)

A Reconstruction of Spinosaurus aegyptiacus 2020

Swimming Spinosaurus (2020)

View of the crocodile-like snout of Spinosaurus and the new interpretation of the tail.

Picture Credit: Davide Bonadonna/National Geographic

The Tale of a Tail

Note the differences in the shape of the tail between the 2014 reconstruction and the very much more fin-like 2020 reconstruction.  The tail of Spinosaurus aegyptiacus has been described as resembling that of a giant crested newt.

Co-author of the scientific paper, Dr David Unwin (University of Leicester), commented:

“The Spinosaurus’ fin-like tail is a game changing discovery for us that fundamentally alters our understanding of how this dinosaur lived and hunted – it was actually a ‘river-monster’.  As well as its tail, many other features of this dinosaur, such as the high position of the nostrils, heavy bones, short legs and paddle-like feet point to a life spent in the water rather than on land.   Not only did dinosaurs dominate the land and take to the air as birds, they even went back into the water and became the top predators there as well.”

Papo Limited Edition Spinosaurus Model (2019)

Historically, some types of dinosaurs were associated with aquatic environments, for example, Jurassic sauropods and duck-billed dinosaurs such as Corythosaurus and Lambeosaurus.  However, these ideas have now been abandoned by most scientists and the Dinosauria is regarded as almost entirely terrestrial.  Recent studies have suggested that the enigmatic spinosaurids, dinosaurs such as Oxalaia, Irritator, Siamosaurus and Ichthyovenator along with Suchomimus, Baryonyx et al, may have been semi-aquatic.  This newly published paper demonstrates that Spinosaurus aegyptiacus possessed a number of anatomical adaptations indicating an aquatic habit.  In 2019, Papo introduced a new, limited edition figure of Spinosaurus, depicting this animal as a semi-aquatic, obligate quadruped.

The Papo Limited Edition Spinosaurus Figure (2019)

Papo Limited Edition Spinosaurus Model.

The Papo Limited Edition Spinosaurus dinosaur model (2019).  This Papo replica depicted Spinosaurus with a fin-like tail, ironically, this shape of tail has now been proposed by vertebrate palaeontologists.

Picture Credit: Everything Dinosaur

A Close-up View of the Thick Tail Adapted for Swimming of the Papo Spinosaurus

Papo Limited Edition Spinosaurus tail.

The tail of the Papo Limited Edition Spinosaurus dinosaur model (2019).

Picture Credit: Everything Dinosaur

Implications for Other Members of the Spinosauridae

Spinosaurus aegyptiacus was one of the last of the spinosaurids.  The authors of the scientific paper postulate that other members of the Spinosauridae are thought to have had aquatic adaptations which suggests a substantial invasion of aquatic environments by this clade of theropods.

Our congratulations to the scientists for their research into this fascinating theropod, we look forward to further papers being published as the Spinosaurus material from the Moroccan site continues to be excavated.  Our congratulations to Papo, for producing a fantastic replica, that although might not depict the dinosaur as exactly as some palaeontologists might, but they do seem to have produced a tail that reflects the newly published scientific data.

Our review of the 2014 paper: Spinosaurus 2014 Scientific Paper Review.

To see the Papo range of prehistoric animal models including the limited edition Spinosaurus: Papo Dinosaurs and Prehistoric Animal Models.

The scientific paper: “Tail-propelled aquatic locomotion in a theropod dinosaur” by Nizar Ibrahim, Simone Maganuco, Cristiano Dal Sasso, Matteo Fabbri, Marco Auditore, Gabriele Bindellini, David M. Martill, Samir Zouhri, Diego A. Mattarelli, David M. Unwin, Jasmina Wiemann, Davide Bonadonna, Ayoub Amane, Juliana Jakubczak, Ulrich Joger, George V. Lauder and Stephanie E. Pierce published in the journal Nature.

8 04, 2020

Lower Triassic Fossil from Brazil – The Origins of the Tanystropheidae

By | April 8th, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Elessaurus gondwanoccidens – Unlocking the Origins of the Bizarre Tanystropheidae

After the mass extinction event that marked the end of the Permian many new types of terrestrial vertebrate evolved.  The archosaurs radiated and developed into a variety of forms, one of the most bizarre groups to emerge were the Tanystropheidae, epitomised by the amazing Middle Triassic Tanystropheus with its hugely elongated neck.  The origin of the tanystropheids remains shrouded in mystery.  The paucity of the fossil record has hindered palaeontologists in their research.  However, a team of scientists have reported the discovery of fossils in southern Brazil that may shed light on the ancestry of these incredible reptiles.

Writing in the academic journal PLOS One, the researchers which include Tiane De-Oliviera of the Federal University of Santa Maria, Brazil, describe and name Elessaurus gondwanoccidens.  It had long legs and very probably a long tail.  The genus name being inspired by the Elvish name (Elessar), a character from Lord of the Rings also known as Aragorn played by Viggo Mortensen in the trilogy of films directed by Peter Jackson.

A Life Reconstruction of the Newly Described Archosauromorph Elessaurus gondwanoccidens

Elessaurus life reconstruction.

A life reconstruction of the newly described Elessaurus from the Lower Triassic of Brazil.

Picture Credit: Márcio L. Castro

An Illustration of the Bizarre Tanystropheus with its Greatly Elongated Neck

A drawing of Tanystropheus.

A drawing of the bizarre Triassic reptile Tanystropheus.  Elessaurus has been described as the sister taxon to the Tanystropheidae.

Picture Credit: Everything Dinosaur

Fragmentary Fossil Material – The Posterior of an Early Triassic Archosauromorph

The fossil material used to describe this new species consists of a partially articulated hind limb and associated fossil elements including parts of the pelvis and caudal vertebrae.  The specimen was collected at the locality Bica São Tomé, Sanga do Cabral Formation (Sanga do Cabral Supersequence, Paraná Basin of southern Brazil).  Based on other fragmentary vertebrate fossils known from this area, the rocks that contained Elessaurus are believed to date from the Lower Triassic.  Although the Elessaurus fossil material represents just a portion of the skeleton and no bones from the anterior part of the animal are known, these fossils represent the most complete post-cranial fossil material obtained to date from the Sanga do Cabral Formation.

Elessaurus Fossil Material (UFSM 11471) and an Accompanying Line Drawing

E. gondwanoccidens fossil material and accompanying line drawing.

Elessaurus gondwanoccidens fossil material and accompanying line drawing showing limb, pelvis and tail elements.  Abbreviations fi = fibula, ti = tibia, gr = groove, fe = femur, il = ilium, sv = sacral vertebra, cv = caudal vertebra.  Note scale bar equals 10 mm.

Picture Credit: De-Oliveira et al (PLOS One)

A phylogenetic assessment of Elessaurus places this genus as a sister taxon to the Tanystropheidae.  The analysis suggests that E. gondwanoccidens was closely related to the tanystropheids and as such it can provide information into the origins of these bizarre reptiles.  Most tanystropheid fossils are found in Middle to Late Triassic rocks of North America, Europe and Asia.  These fossils tend to be strongly associated with marine deposits, indicating that most later tanystropheids adapted to an aquatic or semi-aquatic lifestyle.  The discovery of the closely related but earlier Elessaurus in continental deposits from the Lower Triassic of Brazil, indicates that the origin of this group may lie in the southern continents, the landmass known as Gondwana.  The location of the fossil was the inspiration for the trivial (specific), name of this reptile.  The specific name is derived from the super-continent Gondwana and the Latin adjective “occidens” which means western.

Map (A) Showing the Location of the Fossil Find (B) Stratigraphic Diagram and a Skeletal Reconstruction of Elessaurus

Elessaurus map, stratigraphic profile and skeletal reconstruction.

A map showing the location of the fossil find, along with a stratigraphic profile of the outcrop and a skeletal reconstruction of Elessaurus (known fossil material in grey).

Picture Credit: De-Oliveira et al (PLOS One)

A Terrestrial Animal

The long legs of Elessaurus seem to be suited to a terrestrial existence.  This suggests that the ancestral tanystropheids may have been entirely terrestrial before later species adapted to a more aquatic life.  The discovery of Elessaurus provides a clearer view of the origins of the Tanystropheidae, the scientists hope that further fossil finds will shed more light on the ancestry and evolution of these very unusual tetrapods.

The scientific paper: “A new archosauromorph from South America provides insights on the early diversification of tanystropheids” by Tiane M. De-Oliveira, Felipe L. Pinheiro, Átila Augusto Stock Da-Rosa, Sérgio Dias-Da-Silva and Leonardo Kerber published in PLOS One.

6 04, 2020

Homo heidelbergensis Younger Than Previously Thought

By | April 6th, 2020|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Dating the Broken Hill Skull – H. heidelbergensis Younger than Previously Thought

Palaeoanthropologists have long recognised that the evolution of the hominins and our own species (Homo sapiens), was complicated and not simply a linear transgression from one species to another.  Human fossil remains are exceptionally rare and sometimes, a new study can upend previously assumed concepts and ideas.  For example, a team of scientists including researchers from the Natural History Museum (London), Australian National University (Canberra), University College Dublin, Muséum national d’Histoire naturelle (Paris), University of the Free State (South Africa), University of Wollongong (Queensland), University of Southampton and Griffith University (Queensland), have published new dating information for a hominin skull discovered in 1921.

The skull representing Homo heidelbergensis turns out to be much younger than previously thought.

The Famous Broken Hill Skull (Kabwe 1) Homo heidelbergensis

The famous H. heidelbergensis skull (Kabwe 1).

Views of the Broken Hill Skull (Kabwe 1).  Left lateral view (A) and anterior view (B).

Picture Credit: The Trustees of the Natural History Museum

Writing in the academic journal “Nature”, the researchers conclude that this skull, previously thought to be around half a million years old, was much younger with an estimated date of between 274,000 and 324,000 years of age.  This result suggests that in the later stages of the Middle Pleistocene of Africa (Chibanian stage), there were many different types of hominin living at the same time.  Homo sapiens, H. heidelbergensis/H. rhodesiensis and Homo naledi were all contemporaneous.

The Broken Hill Skull

The skull studied, referred to as the Broken Hill specimen, currently resides in the collection of the Natural History Museum (London) and is on display in the Human Evolution gallery, but there are ongoing discussions about the return of this fossil to Africa.  The skull was discovered in 1921 by an African miner and his Swiss co-worker Tom Zwigelaar at the lead and zinc mine located at Broken Hill, which at the time was in northern Rhodesia but is now Kabwe in Zambia, hence the reference to the fossil skull as Kabwe 1.  Other fragmentary human remains were also found at the mine (partial upper jaw, tibia, sacrum and two elements from a femur from another individual).  The fossils were donated by the mining company to the then British Museum (Natural History Museum), at the time of their discovery anthropologists regarded these fossils as the most significant hominin fossils found on the African continent.

Early Photographs of Kabwe 1 (Broken Hill Skull)

Original photographs of the Broken Hill skull (Homo heidelbergensis).

Original photographs of the Broken Hill skull (H. heidelbergensis).

Picture Credit: Griffith University (Queensland)

Problems Dating the Skull and Fossil Bones

Nearly a hundred years ago, data recording surrounding such an important fossil discovery was nowhere near as thorough at it is today.  Mining work continued in the area where the skull and other bones had been found so any evidence to help accurately date the fossils was subsequently lost.  Assigned to Homo heidelbergensis, the skull was originally dated to around 500,000 years ago.  However, these researchers, led by Professor Rainer Grün (Environmental Futures Research Institute at Griffith University), subjected the skull and the other hominin fragments from the site to radiometric dating and determined that these people lived between 274,000 and 324,000 years ago.

Commenting on the importance of this research, Professor Grün stated:

“The new best age estimate of the fossil impacts our understanding of the tempo and mode of modern human origins”.

One of the co-authors of the scientific paper, Professor Chris Stringer (Natural History Museum), added:

“Previously, the Broken Hill skull was viewed as part of a gradual and widespread evolutionary sequence in Africa from archaic humans to modern humans.  But now it looks like the primitive species Homo naledi survived in southern Africa, H. heidelbergensis was in Central Africa, and early forms of our species existed in regions like Morocco and Ethiopia.”

Homo rhodesiensis and Piltdown Man

It was Sir Arthur Smith Woodward, the curator of the Geology Department at the British Museum who proposed the new species Homo rhodesiensis to describe the Kabwe 1 skull as “Rhodesian Man”.  However, most scientists now consider H. rhodesiensis to be junior synonym of H. heidelbergensis or possibly an African sub-species of it.  Despite a prestigious academic career, Sir Arthur is best remembered for his association with the Piltdown Man hoax of 1912.  Even on his deathbed, he still believed that the fossil remains found in a Sussex gravel bed at Barkham Manor, near to Piltdown Common, represented a species of archaic human, unlike any other species of early hominin known to science.  Unfortunately, for Sir Arthur, five years after he died, new dating techniques proved the human skull bones from the site to be less than 500 years old.

The new, younger date for the Kabwe 1 skull also casts a cloud over the provenance of stone tools associated with hominin fossils from the late Middle Pleistocene.  As scientists have evidence to indicate Homo heidelbergensis present in Africa as recently as 300,000 years ago, stone tools from this date may not have been crafted by our species.

Not All the African Stone Tools Around 300,000 Years of Age Can be Ascribed to our own Species

Heidelbergensis flint spear.

Crafted with considerable skill – a flint spear point associated with Homo heidelbergensis.  The much younger age of the Kabwe 1 specimen casts doubts about which species made the stone tools associated with Middle Pleistocene hominin fossils.

Picture Credit: Dr Nicholas Conrad/University of Tubingen

The new age estimate for Kabwe 1 raises questions about our own evolution.  It casts doubts on the presumption that H. heidelbergensis/H. rhodesiensis was a direct ancestor of our species Homo sapiens.  This research suggests that there were multiple contemporaneous hominin lineages in Africa during the later stages of the Middle Pleistocene, reflecting a similar model found in Eurasia.

  • African hominins (late Middle Pleistocene) – H. sapiens, H. nalediH. heidelbergensis/H. rhodesiensis
  • European/Asia hominins (late Middle Pleistocene) – H. neanderthalensis, H. luzonensis, H. floresiensis, the Denisovans and perhaps also H. heidelbergensis and H. erectus

Everything Dinosaur acknowledges the assistance of a media release from Griffith University in the compilation of this article.

The scientific paper: “Dating the skull from Broken Hill, Zambia, and its position in human evolution” by Rainer Grün, Alistair Pike, Frank McDermott, Stephen Eggins, Graham Mortimer, Maxime Aubert, Lesley Kinsley, Renaud Joannes-Boyau, Michael Rumsey, Christiane Denys, James Brink, Tara Clark and Chris Stringer published in Nature.

To read an article about the presence of H. heidelbergensis in Kent: Giant Prehistoric Straight-tusked Elephant Butchered by H. heidelbergensis.

30 03, 2020

Pterosaurs, Pterosaurs and Even More Pterosaurs

By | March 30th, 2020|Dinosaur and Prehistoric Animal Drawings, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

The “Golden Age” of Pterosauria Research

In the last few weeks, a number of scientific papers have been published detailing new pterosaur discoveries and fossil finds.  We really do seem to be living in a “golden age” of flying reptile research.  For example, researchers have identified the fragmentary fossil remains of three types of pterosaur from the famous Cretaceous Kem Kem beds of Morocco (Anhanguera, Coloborhynchus and Ornithocheirus).  Even before the dust had settled on that publication, another scientific paper, published this week, describes Afrotapejara zouhrii, the newest member of the Tapejaridae, fossils of which also come from the enigmatic Kem Kem beds.

The “Golden Age” of Pterosaur Research – Illustration of Three of the New Pterosaur Types Described

New pterosaur genera described from the Kem Kem Beds of Morocco.

The pterosaur Anhanguera soars over the skies of North Africa with Coloborhynchus and Ornithocheirus to keep it company.

Picture Credit: Megan Jacobs (Baylor University, Texas)

Cretaceous Fossils Mixed Up in a Blender

The Kem Kem Formation is exposed in south-eastern Morocco and neighbouring Algeria.  The extensive deposits represent an inter-tidal, estuarine environment with large, wide lagoons and a broad floodplain criss-crossed by numerous rivers.  These sediments were laid down in the Albian to Cenomanian faunal stages of the Cretaceous, approximately 100 to 95 million years ago.  The terrestrial landscape was dominated by dinosaurs, surprisingly, there seems to have been an overabundance of big theropods present – Spinosaurus, Rugops (other abelisaurs), Sauroniops, Deltadromeus, Carcharodontosaurus, potential dromaeosaurids and a wealth of other fossil bones and isolated teeth that represent indeterminate species.

Trouble is, the transport of material due to river and tidal action has resulted in a mixing up of fossil material.  Fossil beds contain a vast array of jumbled up, disarticulated material, much of which may also have been re-deposited from its original stratigraphic layer.  These deposits have been colourfully described as representing fossils that have been put in a blender, such is their mixing and depositional status.

Typical Isolated and Fragmentary Vertebrate Fossil Remains from the Kem Kem Beds

Fossil remains (Kem Kem beds).

Assorted vertebrate fossil remains from the Kem Kem beds of Morocco.

Picture Credit: Everything Dinosaur

Pterosaurs as Piscivores

In the first scientific paper, researchers from the University of Portsmouth, Baylor University (Waco, Texas), the University of Detroit Mercy (Detroit), Leicester University, the Laboratoire Santé et Environnement (Morocco) and the University of Bath report on the discovery of fragmentary jaws and associated teeth that led to the identification of three new types of pterosaur.  The remains suggest three ornithocheirid pterosaurs, a second species of Coloborhynchus and an Ornithocheirus reminiscent of Ornithocheirus fossil material known from the Cambridge Greensand deposits of southern England.  In addition, a portion of a lower jaw (mandibular symphysis), closely resembles that of the South American ornithocheirid Anhanguera piscator, fossils of which are known from the roughly contemporaneous Romualdo Member of the Santana Formation (Brazil).

An Illustration of Anhanguera (Ornithocheiridae Family)

An illustration of Anhanguera.

A typical member of the Anhanguera genus.  Note the large and very prominent, conical teeth in the jaw.  All three newly described genera are believed to have been primarily fish-eating (piscivores).

Picture Credit: Everything Dinosaur

As well as representing a turbulent depositional environment, the fossiliferous beds of south-eastern Morocco provide an additional challenge for scientists.  Local residents mine the sedimentary rocks, often using only rudimentary tools and materials, so that they can sell their fossil finds to dealers and collectors.  Fortunately, in this case, the fragments of jaw were acquired by scientists enabling a proper academic investigation to be carried out.  The teeth of these pterosaurs suggest that they were probably piscivores, the largest of which probably had a wingspan in excess of four metres.

In the paper, the researchers conclude that the Kem Kem fossil assemblage includes at least nine species of pterosaur, of which the majority (five), are members of the Ornithocheiridae.  These strata help to support the theory that toothed pterosaurs remained diverse throughout the late Early Cretaceous, before going into decline and eventually disappearing after the Cenomanian faunal stage.

And There’s More – Another Moroccan Pterosaur This Time a Tapejarid

New pterosaur discoveries are behaving a bit like buses at the moment (prior to the coronavirus pandemic), three come along and then shortly afterwards another one turns up.  Many of the same scientists from the first academic paper, have published, albeit a little earlier than expected, another paper, this time naming a new species tapejarid pterosaur.  Unlike the other three, this flying reptile was edentulous (no teeth in the jaws).  The newly described tapejarid has been named Afrotapejara zouhrii, based on yet more fragmentary material including jaw elements.

A Typical Illustration of a Tapejarid Pterosaur

Tupandactylus illustration.

A scale drawing of the tapejarid Pterosaur Tupandactylus imperator.  A typical tapejarid – a family of pterosaurs famed for their striking and often over-sized head crests.

Picture Credit: Everything Dinosaur

Fossil jaws seem to be taphonomically selected for in the Kem Kem beds.  Other pterosaur remains have been frequently reported from these deposits, but rarely are the fossils diagnostic.  Isolated mandibular material had hinted at the present of tapejarids in northern Africa in the Early Cretaceous, but Afrotapejara is the first genus to be erected.  It represents the fourth example of a toothless pterosaur taxon to have been described from the Kem Kem beds and it provides the first unambiguous evidence to support the presence of the Tapejaridae in Africa.  The genus name translates as “African tapejarid”, whilst we suspect that the specific name honours Samir Zouhri, one of the authors of the first pterosaur paper reported upon in this blog post.

Based on this evidence, it seems that we really are living in a “golden age” of pterosaur research.

The first scientific paper: “New toothed pterosaurs (Pterosauria: Ornithocheiridae) from the middle Cretaceous Kem Kem beds of Morocco and implications for pterosaur palaeobiogeography and diversity” by Megan L. Jacobs, David M. Martill, David M. Unwin, Nizar Ibrahim, Samir Zouhri and Nicholas R. Longrich published in Cretaceous Research.

The second scientific paper: “A new tapejarid (Pterosauria, Azhdarchoidea) from the mid-Cretaceous Kem Kem beds of Takmout, southern Morocco” by David M. Martill, Roy Smith, David M. Unwin, Alexander Kao, James McPhee and Nizar Ibrahim published in Cretaceous Research.

26 03, 2020

Late Cretaceous Southern United States Had “Raptors” Too

By | March 26th, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Dineobellator notohesperus – A Velociraptorine with Extra Attitude!

Scientists have described a new species of “raptor” from the Late Cretaceous of New Mexico.  Described from fragmentary remains, this two-metre-long carnivore was related to Velociraptor.  It may have been roughly the same size as the Mongolian genus, but it probably was even more agile with a stronger grip.  Its discovery suggests that the dromaeosaurids were diversifying right up to the end of the Age of Dinosaurs.

Life Reconstruction Dineobellator notohesperus (Maastrichtian of New Mexico)

Dineobellator Life Reconstruction

A trio of the newly described dromaeosaurid from the Late Cretaceous of New Mexico (Dineobellator) gather at a waterhole.  The titanosaur Alamosaurus passes by in the background and in the distance a tyrannosaur is approaching.

Picture Credit: Sergey Krasovskiy

Writing in the academic journal “Scientific Reports”, the researchers from The University of Pennsylvania and the New Mexico Museum of Natural History and Science, describe a partial, skeleton excavated from the Bisti/De-na-zin Wilderness of New Mexico, found within a few metres above the base of the Naashoibito Member.  The coarse sandstone deposits are notoriously difficult to date, these sediments were deposited towards the end of the Cretaceous between 70 and 66.3 million years ago (Maastrichtian faunal stage).

Fossil material includes parts of the skull, elements from the jaws, fragments of vertebrae, tail bones (caudal vertebrae), one rib with other pieces of rib and limb bones including a nearly complete right upper arm bone (humerus) and a nearly complete right ulna (bone from the forearm).  The first fossilised remains were found in 2008, subsequent field work carried out in 2009, 2015 and 2016 yielded more fossil material, mostly very fragmentary in nature.  It is believed all the fossil material, including a claw from the right hand, represents the remains of a single dinosaur.

A Skeletal Reconstruction of Dineobellator notohesperus

Known fossil material and skeletal reconstruction of Dineobellator.

A silhouette and postulated skeleton of Dineobellator (known fossil material in white).

Picture Credit: Jasinski et al/Scientific Reports

A Small but Dangerous Dinosaur

Dineobellator notohesperus is the first dromaeosaurid to be described from the southern United States.  It would have lived in the south of the Cretaceous landmass of Laramidia.  Although no evidence of feathers has been found, the ulna shows evidence of a row of small rounded pits in the bone, interpreted as anchor points for large feathers on the arm (ulna papillae).  Analysis of the forelimbs suggest that Dineobellator had stronger arms with a more powerful grip.  A study of the tail bones suggest that the tail had greater movement which would have made this dinosaur adept at making sharp turns and agile changes of direction.  The researchers suggest these anatomical traits provide an insight into how this small theropod hunted and behaved.

The researchers, which include Dr Steven Jasinski (Department of Earth and Environmental Science, University of Pennsylvania), postulate that Dineobellator was an active predator that occupied a discrete ecological niche in the food chain whilst living in the shadow of Tyrannosaurus rex.  The newest North American “raptor” Dineobellator notohesperus is pronounced dih-nay-oh-bell-ah-tor noh-toh-hes-per-us and the genus name comes from the native Navajo word “Diné”, a reference to the Navajo Nation and the Latin word “bellator” which means warrior.  The trivial name has been erected to acknowledge the location of the fossil find.  The word “noto” is from the Greek meaning southern and “hesper” the Greek for western.  This is an acknowledgement that Dineobellator roamed the south-western part of the United States.  In addition, Hesperus is a reference to a Greek god, the personification of the evening star (Venus) and by extension “western”.

Dr Jasinski has already had a considerable impact on the Dromaeosauridae family.  Back in 2015, Everything Dinosaur reported on the formal description of Saurornitholestes sullivani, a dinosaur named by Steven Jasinski whilst a PhD student at the University of Pennsylvania.  To read more about S. sullivaniSniffing Out a New Dinosaur Species.

An Illustration of Saurornitholestes sullivani

Saurornitholestes sullivani illustrated

An agile dinosaur, an illustration of Saurornitholestes sullivani.  Although the fossil material associated with this species was found in New Mexico, S. sullivani lived several million years earlier than Dineobellator notohesperus.

Picture Credit: Everything Dinosaur

A Tough Life for a Tough Dinosaur

A phylogenetic analysis undertaken by the research team places Dineobellator within the Velociraptorinae subfamily of the Dromaeosauridae.  Other Maastrichtian “raptors” known from North America are few and far between (Acheroraptor and Dakotaraptor – both from the Hell Creek Formation).  The discovery of Dineobellator suggests that dromaeosaurids were still diversifying at the end of the Cretaceous and as an velociraptorine, its fossils lend further weight to the idea that faunal interchange between Asian and North American dinosaurs took place sometime during the Campanian/Maastrichtian.

It is not known whether Dineobellator notohesperus was a pack hunter.  The fossilised remains do indicate that this was one very tough dinosaur but it did not have everything its own way.  A rib shows a deformity, suggesting that this bone was broken, but the animal suffered this trauma a while before it died as the break is healed.  Intriguingly, the scientists identified a prominent gouge mark preserved on the hand claw (manual ungual).  This gouge mark, which measures nearly a centimetre long, terminates in a small depression.  The scientists suggest that this damage was not caused by disease or by any process associated with the preservation of the fossil bones.  The team suggest that this was an injury that occurred close to, or at the time of this dinosaur’s demise.

The researchers speculate that this Dineobellator received an injury in a fight with another Dineobellator or perhaps this damage to its hand claw was inflicted upon it by another type of predatory theropod.

Views of the Hand Claw of  Dineobellator notohesperus Showing Damage Interpreted as a Wound Inflicted by Another Theropod Dinosaur

The manual ungual of Dineobellator.

Views of the hand claw of Dineobellator.  The right manual ungual of Dineobellator notohesperus (I) lateral view, with (J) a silhouette of the transverse plane of the right manual ungual near the distal end.  Image (K) shows the claw in media view with the dashed area highlighted in (K) showing the gouge mark (L).  The red arrow indicates the pathology.  Scale bars equal 1 mm, please note (L) is not to scale.

Picture Credit: Jasinski et al/Scientific Reports with additional annotation by Everything Dinosaur

The scientific paper: “New Dromaeosaurid Dinosaur (Theropoda, Dromaeosauridae) from New Mexico and Biodiversity of Dromaeosaurids at the end of the Cretaceous” by Steven E. Jasinski, Robert M. Sullivan and Peter Dodson published in Scientific Reports.

23 03, 2020

Discovery of the Oldest Bilaterian – Ikaria wariootia

By | March 23rd, 2020|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Meet Your Oldest Ancestor – Ikaria wariootia 

A team of international scientists have identified the first ancestor of animals that show bilateral symmetry, in ancient marine sediment around 555 million years old.  Palaeontologists had predicted that such an organism would be identified in Ediacaran sediments, essentially a creature with a body plan that has been adopted by the majority of the Kingdom Animalia, now thanks to the use of sophisticated three-dimensional laser scans funded by NASA, the “smoking gun” evidence has been found.

A Life Reconstruction of the Earliest Bilaterian Known to Date (I. wariootia)

Ikaria wariootia the earliest known bilaterian.

Ikaria wariootia life reconstruction.

Picture Credit: Sohail Wasif/University California Riverside

Ikaria wariootia – The Size of a Rice Grain but a Big Discovery!

Writing in the journal “Proceedings of the National Academy of Sciences of the United States of America”, the researchers, which included scientists from University California Riverside and the South Australian Museum, examined tiny trace fossils, essentially burrows and borings into an ancient Ediacaran seabed (Ediacara Member, South Australia).  Proximal to some of these traces were very small oval impressions.  Thanks to funding from a NASA exobiology grant, the team were able to employ a sophisticated three-dimensional laser scanner to map these depressions in the ancient rock.  Computer-generated images revealed a worm-like organism with a cylindrical body and faintly grooved musculature.  A distinct head and tail were also identified.  This little animal represents the earliest bilaterian, a hugely significant step in the evolution of life on Earth.

The transition from simple, microscopic forms of life to the abundance and variety of complex creatures in the Cambrian remains quite poorly understood.  However, the beautifully preserved remains of soft-bodied organisms, many of which look like nothing alive today, associated with the ancient strata of the Ediacara Hills of South Australia have permitted palaeontologists the opportunity to learn about life on our planet prior to the evolution of hard body parts such as shells and exoskeletons.  Many of the creatures identified from their fossils had bizarre body forms such as the circular Dickinsonia (below), but scientists had predicted that animals with bilateral symmetry would be present in this ecosystem, it was just a question of finding them.

A Circular Impression of an Organism from the Ediacara Hills (South Australia) – Dickinsonia costata Fossil

Dickinsonia costata fossil.

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

Picture Credit: Dr Alex Liu (Cambridge University)

The development of bilateral symmetry was a critical step in the evolution of animal life, giving organisms the ability to move purposefully and a common, yet successful way to organise their bodies.  In the scientific paper, the research team describe Ikaria wariootia as ranging in size between 2 and 7 millimetres in length and being around 1 to 2.5 millimetres wide.   The largest specimens were about the size of a grain of rice, just the right size to have made the burrows and borings (trace fossils).

The discovery of Ikaria wariootia is consistent with predictions based on modern animal phylogenetics, that the last ancestor of all bilaterians was simple and small and represents a rare link between the Ediacaran and the subsequent record of animal life.  Put simply, I. wariootia is on the same part of the animal family tree as the majority of animals alive today and that includes us (Homo sapiens).

Ikaria wariootia Impressions Preserved in Ancient Marine Sediment

Ikaria wariootia impressions.

Ikaria wariootia impressions preserved in ancient marine sediments.

Picture Credit: Droser Laboratory/University of California Riverside

Commenting on the significance of the discovery, one of the authors of the scientific paper, Scott Evans (University of California Riverside), stated:

“We thought these animals should have existed during this interval [Ediacaran], but always understood they would be difficult to recognise.  Once we had the 3-D scans, we knew that we had made an important discovery.”

Analysis of modern animals and Ediacaran trace fossils predicted that the oldest bilaterians would be very small with simple body plans.  The research team found that the size and shape of Ikaria matched the predictions that had been made with regards to the maker of the trace fossil Helminthoidichnites, indicating sediment displacement and purposeful animal movement.  Importantly, in the Ediacara Member, Helminthoidichnites occurs stratigraphically below classic Ediacara body fossils such as Dickinsonia.  Together, these suggest that Ikaria represents one of the oldest total group bilaterians identified to date, with very little deviation from the characters and traits predicted for their last common ancestor.

In addition, these trace fossils persist into the Phanerozoic Eon (from the Cambrian Period onwards),  providing a critical link between the Ediacaran and Cambrian biota.

A Three-Dimensional Laser Image of a Scan of a Rock Depression Revealing the Body Plan of Ikaria wariootia

Three-dimensional laser scan of an Ikaria wariootia impression.

A three-dimensional laser scan of an Ikaria wariootia impression.

Picture Credit: Droser Laboratory/University of California Riverside

What’s in a Name?

The genus name comes from Ikara, which means “meeting place” in the local Adnyamathanha dialect.  It is the Adnyamathanha term for a grouping of mountains known as Wilpena Pound.  The trivial name comes from Warioota Creek, which runs from the Flinders Ranges to Nilpena Station in the Ediacara Hills.  It may look a fairly simple animal to us, but back in the Ediacaran Ikaria was one of the most complex organisms around.  It burrowed in thin layers of well-oxygenated sand on the ocean floor in search of organic matter, indicating rudimentary sensory abilities.  The depth and curvature of Ikaria represent clearly distinct front and rear ends, supporting the directed movement found in the burrows.  The walls of the burrows preserve evidence of “v-shaped” ridges, which indicate that Ikaria moved by contracting muscles across its body like an earthworm.  This is known as peristaltic locomotion.

Everything Dinosaur acknowledges the assistance of a media release from the University of California Riverside in the compilation of this article.

The scientific paper: “Discovery of the oldest bilaterian from the Ediacaran of South Australia” by Scott D. Evans, Ian V. Hughes, James G. Gehling and Mary L. Droser published in the Proceedings of the National Academy of Sciences of the United States of America.

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