All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
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.

1 05, 2020

The First Fossil Frog from Antarctica

By | May 1st, 2020|Animal News Stories, Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

The First Fossil Frog from Antarctica

A researcher from the Swedish Museum of Natural History in collaboration with colleagues from the University of Fribourg (Switzerland) and the Instituto Antártico Argentino based in Buenos Aires (Argentina), has published a scientific paper which provides details of the first fossil remains of a frog to have been found on the continent of Antarctica.

The fossils, consisting of a partial ilium and a bone from the skull which were found in Eocene-aged deposits on Seymour Island, resemble an extant lineage of frogs known as helmeted frogs (family Calyptocephalellidae). Until this discovery, no Cenozoic ectothermic continental tetrapods (amphibians and reptiles), had been documented from Antarctica.  The tiny frog fossils suggest that around 40 million years ago, climatic conditions at high latitudes in the southern hemisphere were still mild enough to support “cold-blooded” amphibians.

A Life Reconstruction of the Helmeted Frog Found on the Antarctic Peninsula (Seymour Island)

Fossil frog described from Antarctica.

Life reconstruction of the frog genus described from the Eocene of Antarctica.

Picture Credit: Pollyanna von Knorring / Swedish Museum of Natural History

Writing in the academic, on-line journal “Scientific Reports”, the researchers conclude that some Eocene freshwater habitats in Antarctica provided habitats that were favourable for cold-blooded (ectothermic) vertebrates such as frogs.  Antarctica was much milder than it is today, the warmest months of the year averaging around 13 degrees Celsius whilst temperatures in the winter would have dropped to below an average of 4 degrees Celsius.  Frogs were present in freshwater ecosystems at a time in the history of Antarctica where ice sheets had formed in upland areas towards the interior of the continent.

Views of the Fragmentary Ilium from Seymour Island

Frog ilium from the Antarctic.

Ilium (NRM-PZ B282) of Calyptocephalella sp. from Seymour Island, Antarctica.  Ilium in lateral (a), medial (b), ventral (c) and dorsal (d) views.  Scale bar equals 1 mm.

Picture Credit: Swedish Museum of Natural History

The fossil frog remains were collected during three joint Argentinian-Swedish expeditions to Seymour Island in the southern hemisphere summers 2011–13.  The bone fragments were concentrated from dry-sieved sediment samples. The closest living relatives of the Eocene specimen are limited to the Chilean Andes (Calyptocephalellidae).  With the discovery of the fossils on Seymour Island, the researchers conclude that these types of helmeted frog were much more widespread across what remained of Gondwana during the Eocene.

The material is housed in the palaeozoological collection of the Swedish Museum of Natural History, Stockholm.

The scientific paper: “First fossil frog from Antarctica: implications for Eocene high latitude climate conditions and Gondwanan cosmopolitanism of Australobatrachia” by Thomas Mörs, Marcelo Reguero and Davit Vasilyan published in Scientific Reports.

Load More Posts