All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
14 01, 2019

Astonishing Basilosaurus – The Apex Predator

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

Research Confirms Basilosaurus Was a Top Predator

Readers with a long memory might remember an episode from the BBC “Walking with Beasts” television series that first aired in 2001.  In this sequel to “Walking with Dinosaurs”, the focus was placed upon the evolution of the mammals after the dinosaur extinction.  “Whale Killer”,  which was episode two in the six-part series, told the story of a pregnant Basilosaurus (archaic whale), desperately searching for food to help the calf growing inside her.  Thanks to raids on Dorudon whales and their young, the Basilosaurus is able to successfully give birth and this episode ends with the mother swimming away with her new-born calf following close behind.

An Illustration of the Fearsome Early Toothed Whale Basilosaurus

PNSO Basilosaurus illustration.
An illustration of Basilosaurus.  The human figure provides scale. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

To view models and replicas of marine prehistoric animals: PNSO Age of Dinosaurs.

Analysis of Basilosaurus Stomach Contents

A team of researchers writing in the on-line, academic journal PLOS One, have published the results of stomach content analysis of Basilosaurus specimens from the Late Eocene-aged site at Wadi Al-Hitan in Egypt.  It is confirmed that Basilosaurus fed on smaller whales (juvenile Dorudon atrox) as well as large fish (Pycnodus mokattamensis).  The scientists, which included Manja Voss (Museum für Naturkunde Berlin) and Mohammed Sameh M. Antar from the Egyptian Environmental Affairs Agency, Cairo, state that this is the first direct evidence of Basilosaurus (B. isis) diet.

A Size Comparison Between an Adult Basilosaurus isis and an Adult Dorudon atrox

An adult Basilosaurus compared to an adult Dorudon whale.
Comparing an adult, fifteen-metre-long Basilosaurus isis museum mounted skeleton to a fully grown Dorudon atrox.

Picture credit: PLOS One/University of Michigan

Basilosaurus – Top of a Tethys Ocean Ecological Pyramid

The Late Eocene Epoch was a time of dramatic change and global extinction.  The once mighty Tethys Ocean was very much reduced, but the first, giant, toothed whales had evolved and the research team cite Basilosaurus isis, the Late Miocene Livyatan melvillei, and the extant Orca (Orcinus orca) as three marine apex predators known from relatively short intervals of time during the Cenozoic.  This research confirms the predator-prey relationship between the two most frequently found fossil whales at the Wadi Al-Hitan location.  Bite marks on the preserved skulls of Dorudon whales suggest predation and not scavenging behaviour by Basilosaurus.

A Photomosaic of a Basilosaurus Specimen (WH 10001)

Basilosaurus scattered remains.
Photomosaic of Basilosaurus isis (WH 10001) from the Gehannam Formation of Wadi Al Hitan.

Picture credit: PLOS One

The image above shows a photomosaic of a scattered and disarticulated Basilosaurus isis specimen from the Gehannam Formation of Wadi Al-Hitan.  The disarticulation of the fossil skeleton and the scattering suggests disturbance by scavengers and possibly long exposure on the seafloor prior to burial.

The researcher conclude that Basilosaurus was a top apex predator that hunted and ate its prey alive, rather than scavenging for scraps.  If the Wadi Al-Hitan site, represents a calving area for the Dorudon, then this would have made an ideal hunting spot for a hungry Basilosaurus.  The dramatic scenes in episode two of the “Walking with Beasts” television series, have more published scientific evidence to back up the screenplay.

The Everything Dinosaur website: Everything Dinosaur.

14 01, 2019

A New Borealopelta Scale Drawing

By | January 14th, 2019|Dinosaur Fans, Everything Dinosaur News and Updates, Everything Dinosaur Products, Main Page, Photos of Everything Dinosaur Products, Press Releases|0 Comments

Borealopelta markmitchelli Fact Sheet Preparations

In a few weeks’ time, the first of the 2019 CollectA prehistoric animal models will be coming into stock at Everything Dinosaur.  One of the first figures expected to arrive is the Age of Dinosaurs Borealopelta figure, a fifteen centimetre long replica of a nodosaurid that roamed north-western Alberta around 112 million years ago.  The fact sheet for this new dinosaur model is being prepared and a scale drawing of Borealopelta (B. markmitchelli) has been produced.

The Scale Drawing of Borealopelta (B. markmitchelli) Prepared for the Everything Dinosaur Fact Sheet

Borealopelta scale drawing.
A scale drawing of the armoured dinosaur Borealopelta from north-eastern Alberta (Canada). Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Heavily Armoured with Countershading

The exquisite state of preservation has permitted palaeontologists to gain a great deal of information about the position of the osteoderms and scutes that covered the dinosaur’s body.  When the scientific paper providing the formal description of Borealopelta was published in 2017, the research team described how chemical analysis of organic compounds in the armour and skin permitted the research team to infer the armoured dinosaur’s pigmentation.

It was discovered that Borealopelta possessed countershading, with a reddish-brown top half contrasting with a much paler underside.  In extant animals, countershading helps to provide camouflage against predators, but most large animals today, such as rhinos, elephants and hippos, don’t have countershading.

The CollectA Age of Dinosaurs Borealopelta Dinosaur Model

CollectA Borealopelta dinosaur model.
The Age of Dinosaurs Popular – CollectA Borealopelta.  Note the paler underside of the animal – an example of countershading.

Borealopelta markmitchelli

At more than five metres long and with such strong armour, it seems surprising that this armoured dinosaur would evolve countershading to help it avoid detection.  Such a large and powerfully built dinosaur would have presented a formidable opponent for most theropod dinosaurs, but apparently it paid Borealopelta to try to maintain a low profile.

It is not known what sort of meat-eating dinosaurs Borealopelta tried to hide from but three-toed prints, some measuring in excess of 90 cm long and ascribed to the ichnogenus Irenesauripis indicate that they may have been some 12-metre-plus carnivores in the ecosystem that were best avoided.

Everything Dinosaur’s original blog post announcing the discovery of the fossilised remains but before a formal scientific description was published can be found here: Extremely Rare Ankylosaur Fossil Turns Up in Alberta’s Oil Sands.

To read an article about the dermal armour of Borealopelta markmitchelli: The Remarkable Armour of Borealopelta.

What Sort of Giant Theropods?

As to what sort of theropods could have predated Borealopelta, we can only speculate.  However, it has been postulated that the super-sized carnivores that Borealopelta was trying to avoid were probably carcharodontosaurids or allosaurids.  This armoured dinosaur is estimated to have weighed more than 1.3 Tonnes, it is much larger than animals alive today that have evolved countershading, therefore, the assumption is that there must have been super-sized, hypercarnivores that Borealopelta was trying to avoid.

Summarising the Research into the Armoured Dinosaur Borealopelta

The research into Borealopelta.
Summarising the research into Borealopelta.

Picture credit: Brown et al, published in Current Biology with additional annotation from Everything Dinosaur

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

The scientific paper: “An Exceptionally Preserved Three-Dimensional Armored Dinosaur Reveals Insights into Coloration and Cretaceous Predator-Prey Dynamics” by Caleb M. Brown, Donald M. Henderson, Jakob Vinther, Ian Fletcher, Ainara Sistiaga, Jorsua Herrera and Roger E. Summons published in Current Biology.

Visit the Everything Dinosaur website: Everything Dinosaur.

Load More Posts