Featured Image Credit: http://www.manchester.ac.uk/
By: Jessica Kittel
While dinosaurs were walking on land, a different group of reptiles, the Ichthyosaurs, were roaming the sea. A recently “rediscovered” fossilized specimen of an Ichthyosaurus, a member of the Ichthyosaur group, has revealed new insight into these fascinating extinct marine reptiles.
Ichthyosaurs as a group were very successful, evolutionarily speaking. Often mistaken as a kind of dinosaur, it turns out they weren’t even in the same group as dinosaurs. They did, however, overlap in their time on the earth. Ichthyosaurs initially appeared on the scene in the Triassic period. It wasn’t until the Jurassic that they reached their peak in diversity and from that time on began to decline. They disappeared sometime during the Cretaceous period. This disappearance was actually millions of years before the dinosaurs went extinct suggesting that whatever it was that did the dinos in, wasn’t likely the same source of the Ichthyosaurs’ downfall.
The particular specimen that has most recently made headlines was an Ichthyosaurus somersetensis, a recently described species of ichthyosaur. This I. somersetensis died roughly 200 million years ago and its fossil was discovered 20 years ago in Somerset, England. The fossil was then taken to Hannover, Germany where she was put on display at the Lower Saxony State Museum. It was here that Sven Sachs, a paleontologist from the Bielefeld Natural History Museum, stumbled upon this specimen and realized it was more than just your average ichthyosaurus.
Sachs teamed up with Dean Lomax, an ichthyosaur expert from the University of Manchester, to pinpoint exactly what they were looking at. It turned out to be an I. somersetensis and has been calculated to be nearly 10 feet in length, the largest fossil of this species to ever be found.
To make this specimen even more fascinating, it turns out that this I. somersetensis was actually pregnant at the time she died. The bones of a not-yet-fully-formed embryo were discovered inside the fossilized remains of her abdomen. The fact that only a few of the bones were preserved suggests that the bones of the embryo were not fully ossified and the embryo was still in the process of developing.
These revelations have given us much more insight into the health and ecology of the prehistoric oceans. As stated by Lomax, “You don’t necessarily have to go out in the field to make a new discovery.”