Sea dragons of Street
Six of us visited this amazing exhibition, put on by the Alfred Gillett Trust, of fossil Ichthyosaurs from about 200 million years ago. These were highly adapted marine predators that lived in the Jurassic Seas that covered what is now Street. Click on any of the pictures below to see them full-size.
The beautiful fossil skeletons that were found in the local Blue Lias rocks show that these ichthyosaurs were the same shape and size as modern dolphins. They were agile swimmers, using flippers for control and a strong tail for propulsion.
Their skulls had long slender jaws with rows of sharp teeth. Behind the jaws are nostrils and huge eye sockets that make up most of the skull, showing them to be surface air-breathers and hunters of small marine creatures.
The layout of the bones in the four flippers show that they evolved from much older land-dwelling ancestors. By 250 million years ago they filled the seas whilst the Dinosaurs, their distant relatives, ruled the land. They went extinct about 90 million years ago.
From these fossils we can tell many other details:-
- fossil skin outlines have preserved the shape of the dorsal fin and tail
- fish and squid have been found amongst their stomach contents
- they gave to live young, tail-first so that the pups wouldn't drown
- their giant eyes were protected by a ring of bony plates like other reptiles and modern birds. This suggests that they hunted their prey at great depth.