LARGEST PREHISTORIC REPTILE FOUND TO BE PREGNANT
The largest known fossilised specimen of a prehistoric species of aquatic reptile called Ichthyosaurus somersetensis has been found in a museum in Germany – and in an unusual twist, it turns out to be that of an expectant mother.
Although sometimes incorrectly referred to as ‘swimming dinosaurs’, ichthyosaurs were in fact an entirely separate order that evolved from land-based reptiles that had returned to the sea, much as manatees and whales have evolved from previously land-based mammals. They ranged in length from 1m to over 20m.
The I. somersetensis fossil in question is of a 3-3.5m adult female. The fossil, which dates back some 200 million years to the Early Jurassic Period, was originally unearthed in the 1990s, but until recently languished in the collection at the Lower Saxony State Museum in Hannover, Germany. That was until it was spotted by palaeontologist Sven Sachs of the Bielefeld Natural History Museum, also in Germany.
Suspecting it could in fact be an
I. somersetensis specimen, Sachs contacted the University of Manchester’s Dean Lomax, who along with his colleague Prof Judy Massare had first described the species. Not only did Sachs’ hunch turn out to be correct, the specimen was also found to contain the fossilised embryo of a baby I. somersetensis, with a preserved section of vertebrae measuring a mere 7cm long.
“It amazes me that specimens such as this can still be ‘rediscovered’ in museum collections,” said Lomax. “This specimen provides new insights into the size range of the species, but also records only the third known example of an Ichthyosaurus with an embryo. That’s special.”
Only three ichthyosaur fossils containing embyros have ever been discovered