Jaws, the prequel: Scientists find the 'Model T Ford' of sharks
By Will Dunham
WASHINGTON (Reuters) - You've heard of the Model T Ford, the famed early 20th-century automobile that was the forerunner of the modern car. But how about the Model T shark?
Scientists on Wednesday announced the discovery of the impeccably preserved fossilized remains of a shark that lived 325 million years ago in what is now Arkansas, complete with a series of cartilage arches that supported its gills and jaws.
Because shark skeletons are made of soft cartilage, not hard bone, finding anything more than scrappy fossilized remains of teeth and vertebrae is rare. Finding a fossil shark in an almost three-dimensional state of preservation, boasting important skeletal structures, is exceptional.
This primitive shark, named Ozarcus mapesae, may lead scientists to rethink shark evolution, erasing the notion that these beasts of the deep have remained little changed since they first appeared at least 420 million years ago.
"These things have been very successful, among the top predators in the Earth's oceans, for over 400 million years," said paleontologist John Maisey of the American Museum of Natural History in New York, one of the researchers.
"The best analogy I can come up with is this: It's like comparing a Model T Ford with a modern automobile. They are both recognizably the same kind of thing. But they are completely different under the hood. We found the Model T of sharks," added Maisey, whose research was published in the journal Nature.
Those cartilage arches, for example, are quite different from those in modern sharks, the scientists said. This suggests that while their general outward appearance has stayed roughly the same, important changes have occurred over time that have helped make sharks the perfect eating machines of the sea.
Maisey said Ozarcus mapesae was small by shark standards - about 2 to 3 feet long, with relatively big eyes. It swam in the murky waters of a shallow inland sea teeming with life including other fish and squid-like creatures in shells. Continued...