Fish preyed on hard-shelled creatures off Jurassic Dorset, say scientists recreating jaw movements
A plate-shaped fish used its thinness to escape being devoured by Jurassic reptiles and chomped on shell creatures off the Dorset coast around 200 million years ago, according to a scientist who recreated its jaw mechanics by examining 89 specimens from three British museums.
© Fiann Smithwick
Fiann Smithwick applied a lever-based model to 89 types of Dapedium from the Natural History Museum, Bristol City Museum and the Philpot Museum in Lyme Regis, measuring the positions and lengths of the jaw bones of the deep-bodied, tiny-mouthed fish group from the Lower Lias rocks.
“My work indicates that Dapedium was well adapted to crush shells, feeding on bivalves and other hard-shelled creatures that it could scrape from the sea floor,” says Smithwick, describing a fish which had jutting front teeth and masses of pebble-shaped teeth further back.
“The outputs showed that Dapedium was a shell crusher,” adds Professor Mike Benton, of the University of Bristol, who oversaw the research.
“Its jaws moved slowly but strongly, and so it could work on the hard shells of its prey.
“Other fishes have fast-moving, but weaker jaws, and those are adapted for feeding on speedy, slippery fish prey.”
Fossil collector Mary Anning discovered the Dapedium during the 19th century. An ancestor of the salmon, cod, seahorses and perch commonly seen today, the species is thought to have avoided being eaten by ichthyosaurs, plesiosaurs and crocodilians thanks to its slender body, which could have made it hard to spot.
- The full paper has been published in Palaeontology.
What do you think? Leave a comment below.
More from Culture24's Science and Nature section:
Scientists discover new species of "uniquely Scottish" boat-sized Jurassic reptile on Isle of Skye
Culture24's top ten Science and Nature stories of 2014
Personal hygiene goods and clothes causing "alarming" sea contamination, say scientists