New species of ichthyosaur was likely a deep-diving squid-eater
Ichthyosaurs were intriguing prehistoric aquatic creatures, in that they looked kind of like dolphins but were actually reptiles. Scientists have now classified a previously-unknown species, that distinguished itself by diving deep.
The new classification was based on a single fossilized skeleton that was carbon dated to the Late Jurassic epoch, which spanned a period about 163 to 145 million years ago. British fossil collector Steve Etches discovered the remains in 2009, along the English Channel coastline in the Dorset region.
It has since been on display at Dorset's Etches Collection Museum of Jurassic Marine Life, and was recently analyzed by paleontologists from Britain's University of Portsmouth. Upon the discovery that it constituted a new genus and species, it was named Thalassodraco etchesi ("Etches sea dragon") in honor of its discoverer.
As compared to other ichthyosaurs, the ~6 foot-long (1.8-m) air-breathing reptile had an extremely deep rib cage, huge eyes, and small, smooth teeth. These features respectively suggest that it had larger than normal lungs, it was able to see well in dim light, and it fed on small prey items such as squid. Such traits would be ideal for making long dives to the dark depths of the ocean, where animals like squid would be plentiful.
It additionally had unusually short flippers and a barrel-shaped body, which probably gave it a distinctive swimming style. As an interesting side note, the ichthyosaurus line began with land-dwelling lizard-like reptiles, the legs of which evolved into flippers as the animals took on an increasingly aquatic lifestyle.
The research is being led by doctoral candidate Megan L. Jacobs and Prof. David Martill. It is described in a paper that was recently published in the journal PLOS ONE.
Source: University of Portsmouth