All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
//August
31 08, 2018

Everything Dinosaur Adds Kaiyodo Dinosaurs

By | August 31st, 2018|Dinosaur Fans, Everything Dinosaur News and Updates, Everything Dinosaur Products, Main Page, Photos of Everything Dinosaur Products, Press Releases|0 Comments

Everything Dinosaur Adds Kaiyodo Dinosaurs

Everything Dinosaur will be adding Kaiyodo dinosaur figures to their model range.  The first of the figures, the limited edition Sofubi Toy Box Tyrannosaurus rex figures will be in stock next month (September).   All three versions of these rare and difficult to obtain articulated T. rex models will be available from Everything Dinosaur including the “smoke green” T. rex and the T. rex “classic colour”.

Everything Dinosaur will be Stocking the Kaiyodo Sofubi Toy Box T. rex Range of Collectables

Sofubi Toy Box T. rex figures available from Everything Dinosaur.

Everything Dinosaur stocks the Kaiyodo Sofubi T. rex dinosaur figures.

Picture Credit: Everything Dinosaur

Kaiyodo Dinosaurs

Back in June, Everything Dinosaur sent a newsletter to the company’s subscribers hinting that these models would be available from the UK-based specialist dinosaur model supplier.  Subscribers were given the opportunity to register their interest and to reserve a figure.  The response has been overwhelming, very few of these models have been produced and they are very difficult to obtain outside of Japan, but these models are shortly to be going on sale at Everything Dinosaur.

For further information on these T. rex collectables and to enquire about reserving a figure email: Contact Everything Dinosaur about Kaiyodo Dinosaurs

A Close View of the Head and the Jaws of Sofubi Toy Box Tyrannosaurus rex – A

Kaiyodo Sofubi Tyrannosaurus rex (A).

Kaiyodo Sofubi T. rex (A).  One of three articulated T. rex models that Everything Dinosaur has access to.

Picture Credit: Everything Dinosaur

Rare Collectables

The three T. rex colour variants are T. rex A, T. rex B (smoke green) and the T. rex (classic image colour).  These are rare collectables and difficult to obtain outside of Japan.  Production of these models has been limited and Everything Dinosaur has been able to acquire stocks of all three of these fantastic figures.  Each model measures approximately 29 centimetres in length and they have ten points of articulation.  The articulated joints are neck, upper jaw, ankles, forelimbs, the base of the tail (proximal end) and the end of the tail (distal).  All the figures have been carefully painted and beautifully designed and engineered.

The Three Sofubi Toy Box Tyrannosaurus rex Figures

Sofubi Toy Box T. rex figures and Everything Dinosaur

Everything Dinosaur and the Sofubi Toy Box Tyrannosaurus rex figures.

Picture Credit: Everything Dinosaur

These models are limited edition collectables and they will have an age restriction on them 15+ (a collectable prehistoric animal figure).

Prices 

The T. rex (A) and the T. rex (B) – smoke green will be priced at £32.99 plus post and packing.  Whilst the rarer, classic colour Sofubi Toy Box T. rex figure will be priced at £37.99 plus P&P.  A spokesperson from Everything Dinosaur did state that it was likely that all three models would be offered to collectors together as a special offer.  The company has offered similar purchasing opportunities in the past, for example, customers were recently given the opportunity to purchase all three Rebor “War Pig” Ankylosaurus magniventris models together at a special discount.

Prices correct as of September 2018.

Thanks to Everything Dinosaur – Collectors Can Get Their Hands on Rare Articulated T. rex Figures 

Sofubi Toy Box T. rex B - smoke green.

Collectors have the opportunity to get their hands on the Sofubi Toy Box T. rex (smoke green).

Picture Credit: Everything Dinosaur

These fantastic and highly collectable Tyrannosaurus rex figures are expected to be in stock at Everything Dinosaur by the middle of September.

30 08, 2018

Illustrating the Rebor Velociraptor “Sweeney”

By | August 30th, 2018|Dinosaur Fans, Everything Dinosaur Products, Main Page|0 Comments

Drawing a Dromaeosaur – The Rebor Velociraptor “Sweeney”

Our thanks to dinosaur model fan Maurizio who sent into Everything Dinosaur a beautiful illustration of the latest Rebor Velociraptor figure, the tiger-striped “Sweeney”.  Rebor have introduced several dromaeosaurid figures, a number of which are Velociraptor models in 1/18th scale.  “Sweeney” joins “Spring-heeled Jack”, “Pete”, “Alex Delarge”, “Gunn”, “Rose” and the first of the Velociraptor scale model replicas to be introduced by Rebor “Winston”.

Maurizio Sent to Everything Dinosaur a Drawing of the Rebor Velociraptor “Sweeney”

Rebor Velociraptor "Sweeney" illustrated.

An illustration of the 1:18 scale Velociraptor figure “Sweeney”.

Picture Credit: Maurizio

Drawing Dromaeosaurids

Dromaeosaurids (family Dromaeosauridae), are geographically widespread with an extensive temporal distribution (Middle Jurassic to the Late Cretaceous).  This family is further divided into subfamilies, however, the exact taxonomic and phylogenetic placement of all the genera is debated.  Velociraptor has two species within the genus and they are members of the Velociraptorinae, along with other Asian “raptors” such as Adasaurus and Tsaagan.  Most scientists believe that these dinosaurs were covered in feathers.  However, Rebor has opted to give their models scales rather than a plumage – a more traditional look to their model figure range.

The Rebor Velociraptor Figure “Sweeney”

Rebor Velociraptor "Sweeney"

The Rebor Velociraptor figure “Sweeney”, part of a range of 1:18 scale Velociraptor models.

Picture Credit: Everything Dinosaur

Maurizio wrote:

“Thank you very much for your co-operation and for your excellent 5-star service.  Just to show you how much I appreciate all of your help, I am sending you an artwork of “Sweeney” that I did for you.  I really hope you like it.”

We do like it, we receive lots of illustrations and we are always impressed by the quality of the drawings, our congratulations to you Maurizio.  It really is a splendid piece of dinosaur inspired artwork.

A Closer Look at the Head of the Velociraptor “Sweeney”

Rebor "Sweeney" illustrated.

A closer view of the head of the “Sweeney” Velociraptor model as drawn by a dinosaur model fan.

Picture Credit: Maurizio

A spokesperson from Everything Dinosaur commented:

“The Rebor Velociraptors have proved to be very popular amongst dinosaur model fans and collectors.  We get lots of complimentary emails about them and, just as on this occasion, we get illustrations of Rebor figures too”.

To view the Rebor “Sweeney” figure and the rest of Rebor replicas product range including the 1:18 scale Velociraptor figures: Rebor Dinosaurs and Prehistoric Animals

Our thanks once again to Maurizio for sending in such a superb dinosaur illustration.

29 08, 2018

Annual Australian Fossil Dig Finds a Fish Lizard Fossil

By | August 29th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Annual Australian Fossil Dig Finds a Fish Lizard Fossil

Each year volunteers as well as experienced field team practitioners and palaeontologists join forces in the Richmond area of Queensland (Australia), to take part in the annual “Big Dig”.  The area surrounding the town of Richmond was once part of a large, inland sea (Eromanga Sea).  Numerous fossils of marine reptiles and other vertebrates have been found and this year, the volunteers have helped with the excavation of a sizeable Ichthyosaur specimen.

This part of Australia presents a challenge for fossil hunters, the area, like most of Australia, has suffered from a prolonged drought, only partially relieved by a short period of seasonal rain that fell a few months ago.  Normally, the ground is baked hard making excavations almost impossible and the temperature can rocket in the Antipodean summer (the winter months in the northern hemisphere), with daily temperatures exceeding 40 degrees Celsius.  As a result, fieldwork tends to be restricted to the slightly cooler months of June, July and August (southern hemisphere winter).

Several fascinating discoveries have been made recently, including the discovery of a bizarre, Cretaceous bird that may have filled the same ecological niche as seagulls today.

To read Everything Dinosaur’s 2017 article about the discovery of the fossils of a prehistoric bird: Prehistoric Seagull from the Outback

Field Team Members Busy Excavating the Ichthyosaur Specimen

A newly discovered Ichthyosaur specimen is excavated

Field team members busy working on the excavation of an Ichthyosaur.

Picture Credit: Michelle Johnston

This year’s dig involved more than a dozen volunteers and experienced researchers from Kronosaurus Korner.  Staff from Kronosaurus Korner organise this annual event and many of the specimens found are prepared and put on display at their museum, which is home to one of the largest collections of Cretaceous marine fossils in Australia.

Kronosaurus Korner curator, Michelle Johnston, explained that a block of stone about 1.8 metres square containing the specimen would be transported back to the museum so that the fossil bones can be properly prepared.  It will take several months of painstaking work to extract the fossils from the surrounding matrix but hopefully, when all the work has been completed, the new Ichthyosaur specimen will be put on display.

An Illustration of a Typical Ichthyosaur

Ichthyosaurus illustration.

An illustration of a typical Ichthyosaur.

Picture Credit: Bob Nicholls @Paleocreations

28 08, 2018

A New Nodosaur from New Mexico

By | August 28th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Invictarx zephyri

Scientists from the Western Science Centre, based in California, have announced the discovery of a new species of armoured dinosaur, a member of the Nodosauridae family of dinosaurs.  The dinosaur is the first new species of dinosaur to be named from fossils found in the Menefee Formation of New Mexico.  This dinosaur fossil discovery suggests that nodosaurids persisted in western North America (Laramidia), throughout the Late Cretaceous, whereas, the closely related ankylosaurids died out in this part of the world as sea levels rose and only became established in Laramidia again millions of years later.   The dinosaur has been named Invictarx zephyri.

A Life Reconstruction of the New Armoured Dinosaur Invictarx zephyri

Invictaryx life reconstruction.

A life reconstruction of Invictarx zephyri.  The illustration provides a view of this new dinosaur from above so that the probable layout of the osteoderms (armour) can be shown.

Picture Credit: Kara Kelley/Western Science Centre

Three Individual Dinosaurs

A total of three individual dinosaurs were found, the first of which was discovered in 2011.  All the specimens were collected from outcrops of the Juans Lake Beds, the upper part of the Allison Member of the Menefee Formation, located in San Juan County (New Mexico).  A precise date for the strata at this locality is difficult to obtain but ammonite fossils found in the overlying marine sandstones suggest that I. zephyri lived some 80 million years ago.  All three specimens consist of highly fragmentary fossil material, although the shape of the osteoderms (dermal armour), along with the stratigraphical position of the fossil material (Lower Campanian aged strata from the Menefee Formation), enabled the researchers to erect a new genus.  As well as the osteoderms, the fossils include rib fragments, a piece of the left humerus, a partial ulna, dorsal vertebrae, an incomplete toe bone and elements from the radii (arm bones).

Reconstruction of the Identifiable Osteoderm Elements in the Three Individual Dinosaurs (Invictarx zephyri)

Invictaryx osteoderms placement.

Dorsal view of the location of osteoderms on the three individual Invictarx specimens.  Scale bar = 50 centimetres.

Picture Credit: PeerJ

The picture above shows the life position of the identifiable osteoderms associated with the three Invictarx specimens (A,C,E).  The holotype specimen is labelled (A).  The drawings below (B, D, F) provide a colour key.  The body outline of Invictarx is not known, so the researchers have inferred the body shape (the illustration above is based on another nodosaurid Sauropelta edwardsorum).

Evidence of a Sacral Shield

Although the remains are far from complete, the researchers writing in the academic journal “PeerJ”, suggest that this dinosaur had a sacral shield (co-ossified pelvic shield), similar to the sacral shield of Polacanthus and Gastonia.  Amongst the osteoderms, potential components of a bony shield were found.  Several other dinosaur fossils from the Menefee Formation have been identified by the research team, including Ornithischian and Theropod remains, these are awaiting formal description, but more new dinosaur taxa are likely to be announced in the future.

Osteoderms of Invictarx (Specimen Number  UMNH VP 28350)

Invictaryx osteoderms.

Osteoderms associated with Invictarx.

Picture Credit: PeerJ

The photograph (above) shows various views of some of the osteoderms associated with Invictarx.  The red box (inset) shows two views of a large piece of armour that probably represents a portion of a broad, rounded plate, an indication that this dinosaur had a sacral shield.

Implications for Nodosaurids and Ankylosaurids in Western North America

Lots of different types of armoured dinosaur have been discovered in North America.  Both nodosaurids and their club-tailed relatives the ankylosaurids are represented.  However, the discovery of an 80-million-year-old nodosaurid in New Mexico, in conjunction with other recent armoured dinosaur finds suggests that whilst the Nodosaurs were present in Laramidia during the Late Cretaceous, the related Ankylosaurs were absent for several millions of years and only re-populated this part of North America towards the very of the Cretaceous period, most likely by migrating into Laramidia across an Asian land bridge.

The Discovery of the Nodosaur Invictarx zephyri Supports the Idea of Nodosaurids Persisting Whilst Ankylosaurs Suffered a Local  Extinction

Ankylosaurs may have suffered a local extinction event in Laramidia.

A timeline showing the geological formations and armoured dinosaur fossil finds.  The red arrow shows the position of Invictarx zephyri.  The red stars indicate nodosaurids whilst the blue stars represent ankylosaurids.

Picture Credit: PeerJ with additional annotation by Everything Dinosaur

The researchers state that the loss of ankylosaurids from Laramidia coincides with the inundation of the Western Interior Seaway in the Cenomanian faunal stage of the Cretaceous, around 100 million years ago.  Ankylosaurs did not re-populate Laramidia until the Campanian faunal stage around 80 million years ago.

The Naming of Invictarx zephyri

The genus and trivial name for this new nodosaurid taxon were inspired by the dinosaur’s armour and the field team’s experience during their first excavation of the fossil material in 2011.  The dig site was situated at the top of a high ridge that was blasted by strong winds.  The name translates from the Latin as the “unconquerable fortress of the western wind”.

27 08, 2018

JurassicCollectables Reviews New Mojo Dinosaurs

By | August 27th, 2018|Dinosaur Fans, Everything Dinosaur Products, Everything Dinosaur videos, Main Page, Photos of Everything Dinosaur Products|0 Comments

A Video Review of the New for 2018 Mojo Dinosaurs

JurassicCollectables have posted up an unboxing video showcasing Papo two prehistoric animals and the new for 2018 Mojo Fun dinosaur models.  Everything Dinosaur sent our friends at JurassicCollectables a parcel containing the Papo Quetzalcoatlus which is going to be reviewed shortly by the talented JurassicCollectables team.  In addition, the box contained a Papo Compsognathus replica, which will be the subject of a JurassicCollectables giveaway coming up soon.  The other four models despatched by Everything Dinosaur were the four new for 2018 Mojo figures, the Giganotosaurus, Deinonychus, Diplodocus and the spectacular blue Baryonyx.

JurassicCollectables Unboxing Video – Papo and Four New Mojo Fun Dinosaurs

Video Credit: JurassicCollectables

Colourful Dinosaur Models

In this brief video (it lasts a fraction under ten minutes), JurassicCollectables provides viewers with an opportunity to get a really close look at the four new and very colourful Mojo Fun figures.  Each of the models is described in detail.  The first to be discussed is the blue Baryonyx, which the narrator, who has not seen the models before, at first, mistakes for a Suchomimus.  Some scientists think that Baryonyx and Suchomimus were very similar, in fact so similar that the fossils found actually describe the same dinosaur.  The validity of the genus Suchomimus has been questioned, so it is quite easy to confuse these two Theropods.  The second model to be discussed, is the spectacular Deinonychus figure.  The narrator from JurassicCollectables confesses that this dromaeosaurid was one of his favourite dinosaurs during his childhood.  The Mojo Fun Deinonychus has a certain “retro” look to it, a point raised during this most informative video review.

The Mojo Fun Deinonychus Dinosaur Model (New for 2018)

The Mojo Fun Deinonychus dinosaur model.

The Mojo Fun 2018 Deinonychus model.

Picture Credit: Everything Dinosaur

To view these new dinosaur models and the entire Mojo Fun Animal Planet range of prehistoric and extinct animals: Mojo Fun Prehistoric and Extinct Animals

Giganotosaurus and Diplodocus

The impressive and sizeable Giganotosaurus figure comes next.  The figure is huge!  It measures thirty-five centimetres in length and it is one of the largest casts every created by Mojo.  Last but not least is the Diplodocus figure.  The long tail is admired by the narrator as is the skin texture and those striking white chevrons that run down the back of the model.  The chevrons have been added as a homage to the genus name.  This famous dinosaur was named after the double-beamed chevron bones found underneath the tail, an anatomical feature once thought to be unique to Diplodocus.

The Mojo Fun Diplodocus Dinosaur Model

Mojo Fun Diplodocus model.

The Mojo Fun Diplodocus dinosaur model.

Picture Credit: JurassicCollectables

The Mojo Fun Diplodocus model is shown in the still from the video (above), the hands provide a “handy” scale.

Mojo Fun Prehistoric and Extinct Animal Models

Mojo Fun have produced four very brightly coloured replicas.  The company has stated their intentions to move away from the more muted model tones of the past and as a result these new figures are very striking.  In the video review, the viewer is given the chance to look at the colour schemes and to examine the replicas in detail.  Mojo Fun have announced that they will be producing re-coloured versions of a number of their existing figures, we at Everything Dinosaur are excited to see the results of the repainting programme.

The Four New for 2018 Mojo Fun Dinosaur Models

Four new Mojo Fun dinosaur models (2018).

The four new dinosaur models from Mojo Fun. Baryonyx and Giganotosaurus (left) with Diplodocus and Deinonychus (right).

Picture Credit: JurassicCollectables

This is an excellent video review of these hard to come by, Mojo Fun figures.  JurassicCollectables have produced lots of amazing prehistoric animal themed videos and their YouTube channel has attracted nearly 75,000 subscribers.  This is an fantastic achievement, Everything Dinosaur recommends dinosaur fans subscribe to the YouTube channel of JurassicCollectables, you can find it here: JurassicCollectables on YouTube.

Our thanks once again to JurassicCollectables for producing such an informative video review.

26 08, 2018

What Might Dinosaur DNA Look Like?

By | August 26th, 2018|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Birds and Turtles Provide a Clue to Dinosaur DNA

Team members at Everything Dinosaur have noted that a number of news channels are covering the story concerning a team of British scientists who have “unpicked” dinosaur DNA and established what it looked like.  Unsurprisingly, references are being made to “Jurassic Park/Jurassic World” and the possibility of having prehistoric animal safari parks sometime in the near future.  As with a lot of science stories, things are not quite what they seem.  Today, we shall endeavour to unravel the double helix behind these news releases and place everything into context.

Not a New Story

The scientific paper that the media is commenting upon was actually published several months ago, appearing in the academic journal “Nature Communications” as an open access article on the 21st May (2018).  Researchers from the University of Kent, in collaboration with scientists from the Natural History Museum (London), the Royal Veterinary College, Cambridge University and Iowa State University, examined the genomes of different species of birds and turtles and as a result, they were able to determine how the overall genome structure of a dinosaur might have looked like under a microscope. Lead author of the scientific paper, Professor Darren Griffin (School of Biosciences, University of Kent) has been studying this area of genetics, looking at the genomes of living species to infer information about extinct ancestors for several years now.

In essence, the researchers set out to extrapolate the possible genome structure of a shared common ancestor between birds and turtles that lived in the Late Permian (260 million years ago), many millions of years before the first dinosaurs evolved.

Extrapolating Dinosaur Genetic Information Based on the Genomes of Extant Descendants

Extrapolating the Structure of the Dinosaur Genome

Working out the structure of dinosaur DNA based on the genomes of extant relatives.

Picture Credit: Everything Dinosaur

It Started with a Chicken

The University of Kent team have been involved in an extensive and long-term programme of research as part of a group called the International Avian Phylogenomics Consortium, whose aim is to better understand the genetics of important domesticated birds such as the turkey, chicken and duck.  Mapping the genome structure of several different types of bird has revealed that the chromosomes of chickens and turkeys have undergone the fewest number of changes compared to their ancient non-avian ancestor – a Maniraptoran dinosaur.

Birds as living descendants of Theropod dinosaurs were thought to have undergone a rapid burst of evolution after the extinction of the non-avian dinosaurs some 66 million years ago.  However, the taxonomic relationship between modern groups of birds is confusing and the molecular details of how birds evolved into more than 10,000 different species today is poorly understood.

Professor Griffin and his team have established that bird genomes are distinctive in that they have more tiny microchromosomes than any other vertebrate group.  These small packages of gene-rich material are thought to have been present in their dinosaur ancestors.  The scientific paper describing this earlier research was published back in 2014 in the journal BMC Genomics.  The team found that the chicken has the most similar overall chromosome pattern to its avian dinosaurian ancestor.  So if you were going to build a real-life “Jurassic Park” start with some domesticated fowls and attempt to de-engineer the genetics, reversing 60 million years plus of evolution, gene mutation and natural selection and you might, just might, end up with a dinosaur.  Sadly, no!  Michael Crichton might have used this idea of genetic manipulation to create dinosaurs, but this technology does not permit you to build a dinosaur.  However, by manipulating the DNA of a chicken embryo it is possible to reveal in that embryo some dormant characteristics and traits that reveal the bird’s dinosaurian ancestry.  For example, researchers have been able to produce an extended pygostyle, turning on those genes once responsible for the formation of the dinosaur tail.  In addition, manipulating the genetic information with the cells of a chicken embryo has led to the development of teeth in the jaws, a trait possessed by dinosaurs but lost by their avian descendants.

Skulls Showing How Genetic Information Can Be Manipulated Between Archosaurs

Tracking the ancestry of the beak in birds.

Normal chick (left), modified chicken embryo (centre), alligator embryo (right), numerous research projects have been undertaken to map the avian genome and to examine the close relationship between living Archosaurs and their extinct relatives.

To read an article from 2009, that looks at attempts to reverse engineer the DNA of chicken embryos to create dinosaur characteristics: The “Dinochicken” Project

Tracing How Chromosomes Have Changed Over Deep Time

The research team’s paper which is currently being commented upon by numerous media outlets (published in Nature Communications, May 2018), used sophisticated mathematical models to map how chromosomes changed over millions of years from a common reptile ancestor to the present day.

Commenting on the significance of this study, Dr Becky O’Connor, (University of Kent) stated:

“The technique used in this study allowed us to determine the genome structure of the turtle-bird ancestor.  Turtles are one of the very few species that have similar looking chromosomes to birds.  Until now, the tools required to compare their chromosomes were not available.  In our study, we added fluorescent labels, called “DNA probes”, to the chromosomes of birds and turtles so that we could locate the stretches of DNA that match in the two species.”

Fluorescent DNA Probes

One of the key pieces of biotechnology that made this study possible was the development of a set of fluorescent DNA probes derived from birds that worked well on the chromosomes of turtles.  Using these probes to identify similarities and differences in the genetic make-up of different, albeit related species, the scientists were able to trace the changes that took place in the DNA of the bird/turtle ancestor and plot the evolutionary path through the Theropod lineage to the modern descendants of long extinct dinosaurs.

Dr O’Connor added:

“The process then involved tracing the changes that occurred from the bird-turtle ancestor.  The evolutionary path examined the point when dinosaurs first emerged, through the Theropod dinosaur line, and beyond several mass extinction events, including the most recent one 66 million years ago.”

The team found that, although the individual chromosomes rearranged their genes internally, this did not occur much at all between the chromosomes, what the scientists describe as “a significant discovery”.

A Dinosaur Production Line As Imagined in the Famous Movies

No dinosaur production line for a very long time.

Scientists will not be scientifically engineering dinosaurs anytime soon.

Picture Credit: Masrani

Lots of Chromosomes Probably Equals Lots of Diversity

Living avian dinosaurs (birds) have a lot of chromosomes, most birds have around 80 chromosomes (40 pairs), compare this to our own species Homo sapiens which as 46 chromosomes (23 pairs).  Having a lot of chromosomes may help to explain why the 10,000 species of birds around today are so diverse.  The pattern of chromosomes (karyotype), in birds may therefore provide clues as to the huge variety of different dinosaurs (non-avian dinosaurs) that once existed.  If early dinosaurs and later Theropods had similar numbers of chromosomes, then this genetic “richness” might explain why non-avian dinosaurs evolved into a myriad of different forms.

This research suggests that, if scientists could take DNA from a Theropod dinosaur such as Velociraptor or even a Tyrannosaurus rex, the chromosomes might look very similar to that of a modern-day bird, remarkably similar in fact to that of a chicken or a turkey.

Buy Why Turtles?

Testudines (turtles, tortoises and terrapins), are not that closely related to dinosaurs.  In fact whether turtles are diapsids and therefore distantly related to dinosaurs and birds, or whether they are anapsids and only very remotely related to dinosaurs and birds is an area of debate.  Most scientists agree that crocodiles are the closet living relatives to dinosaurs (crocodiles are diapsids and also Archosaurs, just like dinosaurs).  However, crocodilian DNA was not used in this research as the team found too many inconsistencies and a lack of success in using the fluorescent DNA probes with crocodilian genetic material.  Furthermore, the crocodilian species studied seemed to show an atypical Archelosaur karyotype with no microchromosome clusters mostly brought about by fusion.

To read an article from Everything Dinosaur about a new fossil discovery that demonstrates just how complicated turtle evolution is: Mosaic Evolution in Testudines – Turtle Evolution is Complicated

In a press release from the Natural History Museum, Dr Paul Barrett explained:

“Turtles aren’t closely related to dinosaurs, but they are one of the living groups of reptiles that can be used to study the relationships of dinosaurs and some of the features that they would have possessed.  Birds are living dinosaurs and crocodiles are their next nearest relatives, followed by turtles, lizards and snakes.”

One thing the researchers are all agreed upon, this study reinforces the idea that birds are essentially living Theropod dinosaurs and despite significant breakthroughs in our understanding of how genetic material might change over deep geological time, no-one is going to be genetically engineering dinosaurs any time soon.

There is Not Going to be a Real Life “Jurassic World” Anytime Soon

Jurassic World premier.

Global success for dinosaur themed block-buster but the science is a very long way behind the cinema.

Picture Credit: Getty Images

The scientific paper:

“Reconstruction of the Diapsid Ancestral Genome Permits Chromosome Evolution Tracing in Avian and Non-avian Dinosaurs” by Rebecca E. O’Connor, Michael N. Romanov, Lucas G. Kiazim, Paul M. Barrett, Marta Farré, Joana Damas, Malcolm Ferguson-Smith, Nicole Valenzuela, Denis M. Larkin and Darren K. Griffin published in Nature Communications.

25 08, 2018

Two New Chinese Dinosaurs Prove Handy

By | August 25th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Plotting the Evolution of the Alvarezsauridae with Bannykus and Xiyunykus

A team of international scientists writing in the journal “Current Biology” have published details of two new Chinese alvarezsaurid dinosaurs that will help palaeontologists to better understand the evolution of this group of bizarre Theropods.  Some later genera becoming the  prehistoric equivalents of today’s aardvarks and anteaters.  The dinosaurs have been named Bannykus and Xiyunykus and their fossilised bones are proving handy, as palaeontologists seek to understand how the Alvarezsaurian dinosaurs reduced and lost most of their digits, except the thumb, which became very large and robust.  These sleek, fast-running and very bird-like dinosaurs seemed to have become very specialised over some ninety million years.

Two Newly Described Chinese Dinosaurs Help to Plug an Evolutionary Gap in the Alvarezsauridae

Chinese fossils shed light on the evolution of the specialised Alvarezsaurian monodactyl hand.

New alvarezsaurid fossils help to shed light on the evolution of the specialised alvarezsaurid hand.  Over millions of years the long forelimbs and three fingered hands evolved into the much reduced limbs with a single digit.

Picture Credit: Vikto Radermacher

The Alvarezsauroidea have a long history, basal forms such as Haplocheirus lived in Asia around 160 million years ago and the very last members of the Alvarezsauridae family were present in the Late Cretaceous, a temporal range of at least ninety million years.  The last of these bizarre, very bird-like dinosaurs have been classified into the sub-clade Parvicursorinae and these animals seem to have been very specialised insect eaters, with a strong single thumb digit with an oversized claw, powerful arm and chest muscles (although the length of the arm was much reduced), long snouts, with thin narrow jaws.  It has been speculated that these dinosaurs could rip apart the nests of termites or dig into logs to find insects.  It has even been suggested that they evolved a long tongue to help them lap up their prey in the same way that an extant anteater does.

The earliest alvarezsaurids were not insectivores, dinosaurs like Haplocheirus were probably hunters of small vertebrates.  Haplocheirus (H. sollers), had the teeth of a typical meat-eating Theropod and grasping hands to catch prey.  Only later alvarezsaurids had much reduced teeth and evolved a hand with a single, large curved thumb claw.

Digit Reduction in Tetrapods

The loss of fingers and toes has occurred numerous times amongst Tetrapods.  Perhaps the most famous example of all, is the evolution of the foot of the horse.  It was the notable American palaeontologist Charles Othniel Marsh, who plotted the evolution of equines by studying the toe bones of ancient horses.  Marsh was able to demonstrate how primitive horses gradually lost their toes evolving into the single-toed, fast running animal we know today.

To read more about the contribution of Marsh and the evolution of horses: The Contribution of Othniel Charles Marsh

Both Bannykus and the slightly smaller Xiyunykus are important because they show transitional steps in the process of Alvarezsaurs adapting to new diets.

Mapping the Evolutionary History of the Alvarezsauroidea

Alvarezsaurid evolution.

The discovery of two new Chinese alvarezsaurids helps to plug a seventy million year gap in the evolutionary history of the Alvarezsauroidea.

Picture Credit: Current Biology

The image (above) shows the temporal position of the two, newly described species.  Both Xiyunykus and Bannykus lived during the Early Cretaceous, their fossils are helping to bridge a seventy million year gap between Late Jurassic basal forms and the advanced and highly specialised Late Cretaceous forms.

Xiyunykus pengi

Xiyunykus was the first of these new dinosaurs to be discovered.  Its fossils were found in 2005, by an international expedition to the Junggar Basin (Xinjiang Uyghur Autonomous Region of north-western China).  The fossil remains consist of a partial, disarticulated skeleton and the material has been dated to the Barremian-Aptian faunal stages of the Early Cretaceous.  The researchers, including Xu Xing from the Institute of Vertebrate Palaeontology and Palaeoanthropology (IVPP) have estimated that this dinosaur weighed around fifteen kilograms.

Skeletal Remains of Xiyunykus pengi

Xiyunykus pengi fossils.

Xiyunykus pengi fossil material.  Picture A shows a skeletal outline (scale bar 10 cm), the known fossil material is shaded grey, whilst B, shows a cross-section through the fibula used to give an approximate age for the specimen.  Images C-N show various fossil elements used to identify and define the species.

Picture Credit: Current Biology

A cross-sectional analysis of lower leg bone (B) in the image above, indicates that this dinosaur was around nine years of age when it died and probably a sub-adult.  The genus name is from “Xiyu”, the Mandarin for denoting the western regions of Central Asia and from the Greek “onyx” meaning claw.  The trivial name honours Professor Peng Xiling, who has played a significant role in the study of the geology of this region.

 Bannykus wulatensis

The second alvarezsaurid was discovered in 2009 in western Inner Mongolia.  The fossils come from the Bayingobi Formation  (Aptian faunal stage of the Early Cretaceous).  Histological analysis of a cross-section of bone taken from the fibula indicates that this dinosaur was around eight years of age when it died. It, like the Xiyunykus specimen, was probably a sub-adult.

Skeletal Remains of Bannykus wulatensis

Bannykus wulatensis fossil material and skeletal drawing.

Skeletal remains and a limb bone cross-section with an accompanying line drawing of Bannykus (known fossils shaded grey).  Bannykus wulatensis shown as a skeletal drawing (A), note scale bar equals 10 cm, with (B) showing the cross-section of the fibula.  Images C-O represent elements of the fossil material.

Picture Credit: Current Biology

The genus name comes from the Mandarin “Ban” meaning half, a reference to the transitional anatomical features seen in this dinosaur and “onyx”, from the Greek for claw.  The trivial name refers to Wulatehouqi (Wulate Rear Banner), the county-level administrative division in which the type locality is situated.

Long Arms and Grasping Hands to Reduced Arms and Digits

These two newly described Alvarezsaurian dinosaurs have helped to determine that these peculiar Theropods very probably originated in Asia, before migrating to other parts of the world such as North and South America over their long evolutionary history. Bannykus and Xiyunykus are important because they show transitional steps in the process of Alvarezsaurs adapting to new ecological niches, Bannykus, which may have lived slightly later than Xiyunykus, is showing signs of that mechanically efficient forearm, a more robust and powerful upper arm and an enlarged thumb.

The Manus (Hand) of Bannykus Showing a Transitional Stage in Alvarezsaurid Evolution

Image of the fossil bones comprising the Bannykus hand.

A digital image of the fossil hand of Bannykus.  Note the larger thumb with proportionally bigger bones and a big claw (hypertrophied first digit).

Picture Credit: Current Biology

Still a Puzzling Group of Bird-like Dinosaurs

The discovery and scientific description of these new members of the Alvarezsauridae is very significant.  These fossils will help scientists to better understand the evolution of the specialised hand of alvarezsaurids and provide assistance when it comes to phylogenetic placement for group members.

Lead author of the scientific paper, Xu Xing commented on the evolutionary changes that had been highlighted stating:

“This transition plays out in an incremental fashion over more than 50 million years.  It could one day potentially serve as a classic example of macroevolution akin to the ‘horse series’ of North America.”

These dinosaurs are some of the more bizarre and peculiar forms of Theropod.  Ancestral forms seemed to have anatomical features quite typical of carnivorous dinosaurs, before evolving much more specialised forms, probably in response to exploiting a particular ecological niche.

Co-author James Clarke (George Washington University), added:

“The fossil record is the best source of information about how anatomical features evolve and like other classic examples of evolution such as the “horse series,” these dinosaurs show us how a lineage can make a major shift in its ecology over time.”

The Alvarezsaurian dinosaurs remain a puzzle.  They may have evolved into specialist insectivores, but they retained their long legs and the ability to run fast throughout their evolutionary history.  The forelimbs, hands and digits may have undergone a radical change, but these dinosaurs always seem to have remained quite graceful and agile animals.  Why these animals retained their ability to run very quickly when their prey was to be found in a termite mound or a rotting log is not clear.  However, it is likely, that the ability to run fast was continued to be selected for in this group as an adaptation to avoiding being eaten by larger predatory dinosaurs.

Palaeontologists Xu Xing and James Clarke Searching for Dinosaur Fossils

Scientists looking for alvarezsaurid fossils.

Xu Xing (IVPP) collecting fossils with James Clark (George Washington University).

Picture Credit: Xu Xing

The scientific paper: “Two Early Cretaceous Fossils Document Transitional Stages in Alvarezsaurian Dinosaur Evolution” by Xing Xu, Jonah Choiniere, Qingwei Tan, Roger B.J. Benson, James Clark, Corwin Sullivan, Qi Zhao, Shuo Wang, Hai Xing and Lin Tan published in Current Biology.

24 08, 2018

First Diagnosis of Septic Arthritis in a Dinosaur

By | August 24th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

A Very Poorly Duck-billed Dinosaur

A team of scientists, including a researcher based at the University of Manchester, have identified a case of septic arthritis in a dinosaur bone.  This is the first documented case of this crippling condition to have been identified in the fossilised bones of a dinosaur.  It is likely that the poor, unfortunate dinosaur, a hadrosaurid, struggled with painful joints for some time before it died.

The fossil bones, an ulna and radius (bones from the arm), were found in the Upper Cretaceous deposits of the Navesink Formation (New Jersey, USA).  The strata were laid down in a near shore marine environment and dinosaur bones are exceptionally rare from these sediments, the ulna and radius were found fused together, but they were subsequently separated.

The ulna has a preserved length of 67.5 cm and the radius is slightly smaller at around 53.5 cm.

Bones from a Member of the Hadrosauridae?

The bones were compared to other hadrosaurid forelimb material and based on this analysis they were assigned to the Hadrosauridae (duck-billed dinosaurs), like many of the dinosaur fossil bones from eastern North America (Appalachia), these two bones could not be assigned down to the genus level.  Writing in the open access journal “Royal Society Open Science”, the researchers refer to the specimens as coming from an indeterminate hadrosaurid.

A Drawing of a Hadrosaurid Which May Have Been Similar to the Navesink Formation Specimen (NJSM GP11961)

Gryposaurus scale drawing.

A Gryposaurus scale drawing.  Many of the duck-billed dinosaur fossils from eastern North America are not assigned to any particular taxon.  However, most of the Hadrosauridae fossils found in this area are believed to have come from dinosaurs similar to Gryposaurus or Edmontosaurus in appearance.  Based on the limb measurements (preserved lengths), it is likely that the bones came from a large animal, about the size of the dinosaur depicted in the scale drawing.

Picture Credit: Everything Dinosaur

Non-destructive Method of Viewing the Internal Structure of Fossil Bone

Historically, when palaeontologists have decided to assess the condition of a bone’s interior this has resulted in severe damage to the specimen. Prior to the use of X-ray microtomography (CT scans), the fossil bone would have had to be sectioned in order to reveal details of the inside. However, CT scans and other such non-invasive methods have enabled researchers to assess features inside the fossil in a non-destructive way. In this study, the ulna and radius (NJSM GP11961), were subjected to detailed cross-sectional CT scanning to assess the extent of the pathology present inside the fossil bones.

Pathology (Septic Arthritis) Identified in the Hadrosaurid Ulna

Septic arthritis in a hadrosaurid ulna.

Septic arthritis identified in fossil dinosaur bone.

Picture Credit: Royal Society Open Science

The picture above shows the hadrosaurid ulna (NJSM GP11961) in several views.  The scientists identified a large area of roughened and remodelled bone towards the proximal articulation with the radius surface (PRU).  Large lesions caused by the condition were found.  The section of bone in the red box shows that portion of the fossil that was subjected to X-ray microtomography.

X-ray microtomography Reveals the Extant of the Damage to the Ulna

CT scans show septic arthritis in a dinosaur bone.

X-ray microtomography of the ulna providing a cross-sectional analysis of the pathology.

Picture Credit: Royal Society Open Science

Note the scale bar is 1 cm.  The lines labelled a to d in the image on the far left show the transverse sections on the ulna which correspond to the other four images shown.  Abnormal, well-developed bony projections (enthesiophytes), are highlighted by the red arrows (images a and c).  Necrosis (dead bone) is seen in b (circled in red) and remodelled bone growth is shown in both c and d (also outlined in red).

Comparing the Dinosaur’s Condition to Similar Conditions Found in Living Reptiles and Birds

The researchers, which included scientists from the University of Massachusetts and the New Jersey State Museum as well as Manchester University, looked at similar conditions seen in poultry and living reptiles and concluded that the abnormal bone growth, lesions and remodelled bone were likely caused by a form of osteoarthritis (arthritis in the bone).  Diagnosis was based on the erosion of the joint and highly reactive periosteal bone growth and fusion of the elements.  This condition is caused by the loss of cartilage and it would have been very painful for the animal.  Osteoarthritis in birds and reptiles is usually a consequence of disease, bacterial infection or trauma.  The scientists were not able to state with any certainty how the condition came about, but at some point in this duck-billed dinosaur’s life it either had an accident, was attacked or caught an infection that led to this secondary condition.  What the scientists were able to state was that this dinosaur lived with this painful condition for some time before it died.

Septic Arthritis Identified in the Hadrosaurid Radius

Hadrosaurid radius with septic arthritis.

The hadrosaurid radius showing the septic arthritis.

Picture Credit: Royal Society Open Science

The picture above shows the hadrosaurid radius (NJSM GP11961), the red box indicates the area that was subjected to X-ray microtomography.  The radius shows heavy reactive bone growth on the proximal articulation surfaces.  In the picture, PRU (proximal articulation surface with the ulna), shows extensive pathological bone growth, described by the researchers as having a “cauliflower-like” appearance.  The scientists noted that the distal articular surface with the ulna had eroded, most of the vertebrate fossils from the Navesink Formation tend to consist of isolated fragments, often quite heavily eroded due to taphonomy.

Septic arthritis is usually localised in reptiles, unlike in people, where the condition can spread throughout the body.  However, as only the ulna and radius were found the extent to which the rest of the dinosaur’s body was affected is not known.

23 08, 2018

Turtle Evolution – Complicated

By | August 23rd, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Oldest Turtle with a Beak but No Shell – Eorhynchochelys sinensis

A beautifully preserved and very nearly complete fossilised skeleton of a turtle is helping scientists to unravel the evolutionary story of these ancient reptiles.  However, it seems that the evolution of turtles, tortoises and terrapins (the Order Testudines, sometimes referred to as the Chelonii), may be even more complicated than previously thought, just like a large terrapin in a small aquarium, the discovery of this new fossil, might just have muddied the water somewhat.

A Life Reconstruction of the Newly Described Late Triassic Turtle Eorhynchochelys sinensis

Eorhynchochelys sinensis life reconstruction.

A life reconstruction of Eorhynchochelys sinensis.

Picture Credit: Yu Chen (Institute of Vertebrate Palaeontology and Palaeoanthropology)

Early Turtle From the Late Triassic

The skeleton was excavated from Upper Triassic rocks in Guanling County, (Guizhou Province, south-west China).  It has been named Eorhynchochelys sinensis, the name means “dawn turtle with a beak from China”.  As the scientific name suggests, this is the oldest turtle ever found with a toothless beak.  Its discovery might help to close a gap in the evolutionary history of the Chelonii, as although it did not have a shell (the fossil lacks a carapace or plastron), the skull is very similar to the skull of extant turtles, but the rest of the animal’s skeleton resembles that of an earlier basal turtle that lived some ten million years previously.  Eorhynchochelys was over two metres long and it lived in an estuarine environment, it was most likely amphibious and the presence of strong claws and well-developed forelimbs suggests that this ancient animal may have lived in a burrow.

A View of the Fossil Material E. sinensis

Eorhynchochelys sinensis fossil - an early turtle without a shell.

Eorhynchochelys sinensis fossil (dorsal view).

Picture Credit: National Museums of Scotland

Mosaic Evolution

The researchers, which included scientists from the National Museums of Scotland, the Chicago Field Museum, the Canadian Museum of Nature and the Institute of Vertebrate Palaeontology and Palaeoanthropology in Beijing, were intrigued by the modern-looking turtle skull with its characteristic edentulous (toothless) beak.  This feature had not been seen in early fossil turtles before and the dating of  Eorhynchochelys indicates that this trait seems to have disappeared in some lineages and reappeared millions of years later.  This suggests that the evolutionary development of the Chelonii was much more complicated, after all, here was a Late Triassic ancestral turtle with a modern-looking skull but lacking a shell, although the broad, enlarged ribs and other anatomical features of the skeleton indicated that this type of reptile was on the way to evolving such a feature.

The fact that Eorhynchochelys developed a beak before other early turtles but didn’t have a shell is evidence of mosaic evolution, the idea that characteristics can evolve independently from each other and at a different rate and that not every ancestral species has the same combination of these traits.  All living turtles have both shells and toothless beaks, the evolutionary path that led to these traits was not a simple linear progression.  Some ancient turtles evolved partial shells, whilst others evolved beaks, eventually the genetic mutations and natural selection that allowed these traits to develop became unifying characteristics of the group as a whole.

A Life Reconstruction of the Head of Eorhynchochelys

Eorhynchochelys sinensis with its beak.

An illustration showing the head of Eorhynchochelys sinensis with its beak.

Picture Credit: Institute of Vertebrate Palaeontology and Palaeoanthropology

Family Links

Although the discovery of Eorhynchochelys sinensis helps to provide further information on the evolution of turtle traits, it does not resolve a long-standing argument about where in the Class Reptilia the Testudines (Chelonii), should be placed.  However and whenever these reptiles evolved their characteristic features might be complicated, but it seems that by around 210 million years ago, the turtle body plan with its carapace, plastron and beak had come about and this group have remained relatively unchanged since.  The Testudines seem to lack a feature that is common in most other reptiles, a pair of holes (fenestrae), in their skulls behind the eyes.  For many years, turtles were thought to be anapsids (members of the  Anapsidae), a very primitive subclass of the Reptilia.  Genetic studies have suggested that turtles, tortoises and terrapins are closely related to diapsid reptiles and their close relatives, Archosaurs such as crocodilians, dinosaurs and birds.  However, other studies have concluded that turtles and their kind might actually, be more closely related to snakes and lizards (Squamata).

Eorhynchochelys had a single pair of holes behind its eye sockets, this might suggest an anapsid origin or it might indicate that Eorhynchochelys is a transitional form that evolved from diapsid ancestors.

Commenting on the taxonomic position of the Chelonii in the light of this new Chinese fossil discovery, co-author of the research, Xiao-Chun Wu (Canadian Museum of Nature), explained that when the physical characteristics of Eorhynchochelys were considered in an analysis with other fossilised reptiles, it is likely that turtles are not closely related to either the Archosauria or the Squamata, but it is more likely that they are an offshoot from earlier, more primitive reptiles.

In the absence of more fossils, this debate is not going to be resolved anytime soon.

To read an article from 2013 looking at research into the evolution of Chelonians: How the Turtle Got Its Shell

For an article that discusses the discovery of Pappochelys rosinae a basal turtle that lived some 20 million years earlier than Eorhynchochelys, that has been classified as a diapsid but had the beginnings of a plastron: Pappochelys – The Grandfather of the Chelonii

22 08, 2018

A Challenge to the Aquatic Spinosaurus Theory

By | August 22nd, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Was Spinosaurus aegyptiacus at Home in the Water?

New research utilising computer modelling to study the buoyancy of Spinosaurus (S. aegyptiacus) by Dr Donald Henderson of the Royal Tyrrell Museum (Alberta, Canada), challenges the idea that this sail-backed Theropod was adapted for a semi-aquatic way of life.  The research suggests that Spinosaurus could float and keep its head clear of the water to enable it to breathe, but other Theropods could also float in positions that enabled them to breathe freely, but with its pneumatised skeleton and system of air sacs, diving for food was probably beyond Spinosaurus, thus hindering its ability to be an effective semi-aquatic, pursuit predator.  Dr Henderson concludes that Spinosaurus may have been more at home wading through water, specialising in hunting along the shoreline or in shallow water, but still remaining a competent terrestrial predator.

Spinosaurus May Have Been a Shallow Water or Shoreline Predator

Spinosaurus

From paddler to swimming the “evolving” image of Spinosaurus.  New research proposes that Spinosaurus aegyptiacus was a shallow water predator and not capable of diving for its dinner.

Picture Credit: Everything Dinosaur/BBC

Challenging the 2014 Scientific Paper

Dr Henderson set about creating three-dimensional computer models of Spinosaurus and several other Theropods including Allosaurus, Coelophysis, the ornithomimid Struthiomimus, Tyrannosaurus rex and another member of the Spinosauridae family – Suchomimus tenerensis.  Dr Henderson, who is the Curator of Dinosaurs at the Royal Tyrrell Museum of Palaeontology, located in Drumheller, southern Alberta, wanted to test the hypothesis proposed by Dr Nizar Ibrahim and colleagues published in September 2014, that hypothesised that S. aegyptiacus was quadrupedal and a semi-aquatic dinosaur, a first for a member of the Theropoda.

To read Everything Dinosaur’s article about the 2014 scientific paper: Spinosaurus – Four Legs are Better than Two

Intriguingly, the interpretation of Spinosaurus, as proposed by Ibrahim et al, was used as the basis for the digital Spinosaurus model by the Royal Tyrrell Museum researcher.

Views of the Theropod Body Plans Used to Test Buoyancy

Digital models of Theropods used in floatation tests.

Theropod body plans used in the floatation tests, dorsal and lateral views.

Picture Credit: PeerJ/Dr Henderson (Royal Tyrrell Museum)

The picture above shows the digital body plans used to test the theoretical buoyancy of different types of Theropod dinosaur.

Key

A).  Coelophysis bauri

B).  Struthiomimus altus

C).  Allosaurus fragilis 

D).  Suchomimus tenerensis (Baryonyx tenerensis) – it has been suggested that Suchomimus and Baryonyx fossil material might represent the same genus (Holtz, 2012; Sues et al., 2002), this conclusion was used in this study.

E).  Spinosaurus aegyptiacus – the body plan based on the body shape proposed by Ibrahim et al in the 2014 paper.

F). Tyrannosaurus rex

Testing Buoyancy in Freshwater

To ensure that the digital models were able to replicate the orientation and depth of immersion in freshwater, Dr Henderson tested the software using a model of an alligator (A. mississippiensis).  Furthermore, he assessed the buoyancy of a computer generated model of an emperor penguin (Aptenodytes forsteri), which is also a member of the Theropoda.

Dr Henderson explained:

“Science is self-correcting.  Research is a competitive scientific process that continually generates new information and ideas, so here’s some of the self-correcting in action.”

Testing the Stability and Buoyancy of Spinosaurus (S. aegyptiacus)

Testing the buoyancy and stability of Spinosaurus.

Testing the stability and buoyancy of Spinosaurus in freshwater.

Picture Credit: PeerJ/Dr Henderson (Royal Tyrrell Museum)

Spinosaurus Could Float But So Could Other Theropods

Dr Henderson’s digital models demonstrated that Spinosaurus could indeed float with its head above water, enabling it to breathe freely.  However, the models of other Theropod dinosaurs demonstrated similar results.  This was not unexpected as most Tetrapods can successfully float and swim, the shape of Spinosaurus did not necessarily give it an advantage over the body shape of other dinosaurs when it came to stability in water.

Alligators Much Better Suited to Water Than Spinosaurus

The stability of a Spinosaurus in freshwater was also compared to the digital alligator. When tipped to the side, the alligator model returned to its original topside position.  Such behaviour is seen in semi-aquatic animals, they have the ability to right themselves when floating.  The Spinosaurus model did not perform well in the same tests.  When tilted, the model rolled over onto its side, demonstrating very little lateral stability in water.  The research implies that Spinosaurus would have easily tipped over and would have had to use its limbs constantly to maintain an upright posture in the water.

Based on the Digital Model Analysis Alligators Are Much Better Suited to an Aquatic Habit Than Spinosaurus

Alligator swimming.

An American alligator.

Picture Credit: Everything Dinosaur

Assessing the Centre of Mass

One of the key points of the 2014 paper, was that an anatomical study based on the known Spinosaurus fossil material (which represented numerous individuals of different sizes), indicated that this dinosaur walked on all fours.  In this new research, the centre of mass of the digital model of Spinosaurus was found to be close to the hips, similar to what is seen in other Theropods.  This contradicts the 2014 research, as Dr Ibrahim and his colleagues proposed that S. aegyptiacus had a centre of mass located towards the centre of the torso.  With the centre of mass located further forward, it suggests a quadrupedal form of locomotion, however, Dr Henderson’s research indicating a centre of mass positioned over the hips suggests that Spinosaurus could have walked around on land quite happily on just its hind legs (bipedal).

The Position of the Centre of Mass Would Affect Locomotion on Land

Different interpretations of Spinosaurus fossil material.

Different interpretations of the body plan of Spinosaurus.  The red asterisk suggests the centre of mass for each figure.

Picture Credit: Everything Dinosaur

Spinosaurus Probably Couldn’t Dive

Dr Henderson’s models also found Spinosaurus to be unsinkable.  Living aquatic birds, reptiles, and mammals all have the ability to submerge themselves to pursue their prey underwater. Although the bones of Spinosaurus might be more dense than other carnivorous dinosaurs, they still were substantially pneumatised.  This anatomical feature in conjunction with the air sac breathing system found in living Theropods (birds), probably made it very difficult, if not impossible, for this dinosaur to dive underwater in search of prey.

Dr Henderson concludes that this inability to dive, combined with a centre of mass close to the hips and a tendency to roll onto its side, suggests that Spinosaurus was not a specialised semi-aquatic predator after all.

He added:

“Spinosaurus may have been specialised for a shoreline or shallow water mode of life, but it would have still have been a competent terrestrial animal.”

However, as there are so very few Spinosaurus fossil bones to study, it is possible that this dinosaur lacked a significant number of avian style air sacs and pneumatised bones.  Even with an increased mass offered by a denser skeleton the digital model when “tweaked” in this way, still suggested that being able to submerge and go underwater would have been a considerable challenge.  Dr Henderson does concede that if it could be shown that the mass deficit represented by the lungs and air sacs was offset by the increased mass of a denser skeleton that might help the claim of a semi-aquatic Spinosaurus.

This is essentially, the central point of the Spinosaurus controversy.  This dinosaur did live in a habitat dominated by large bodies of water.  There were plenty of large fish around for an aquatic predator to eat, but in the absence of fossil evidence, the actual role of Spinosaurus in the North African Cretaceous ecosystem and its habits remain very much open to debate.

The scientific paper: “A Buoyancy, Balance and Stability Challenge to the Hypothesis of a Semi-aquatic Spinosaurus Stromer, 1915 (Dinosauria: Theropoda)” by Donald M. Henderson and published in the academic on-line journal PeerJ.

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