Friday, 15 February 2013

The Mosaleum Part 2, Mosasaur Bones

After death the mosasaur sank to the bottom of the sea, where it was scavenged before being covered in sediment and fossilizing.  Most of the skeleton was scattered, but the skull and much of the spine has been found.

Bitemarks, indicated by arrows
The bones in the Mosaleum in fact preserve evidence of being scavenged in the form of bitemarks. Beyond the bitemarks, there is also further evidence identifying the culprits.

Sharks are among the largest scavengers in the sea, and when they get their fill they often shed a few teeth. Which is also what happened in this case. and it is by it's teeth that we know the shark.

Shark's teeth found with the Mosasaur skeleton

In fact two types of shark teeth were found with bones of this Progathodon, one type belonged to the 3 meter long Squalicorax while other teeth belonged to the smaller Plicatoscyllium. Both species would certainly have been small enough to be considered a snackfood by P. saturator when it was alive.

Life reconstruction of Squalocorax by D. Bogdanov

The scavenging sharks also inspired the species name saturator, which according to the paper describing it means "he who gives satisfaction (both to Maastrichtian sharks as well as Recent palaeontologists)". 

Most of the skeleton of Bèr was scattered by the scavengers and the sea, but the remains of the spine that have been recovered are on display under the floor of the Mosaleum. 

The spine and ribs of Prognathodon saturator

It's a very nice display. And while the amount of text is small it does a very good job of highlighting what is important and interesting,