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Fossil Evidence of Giant Ancient Fish

Some 100 million years after swimming the churning sea that is now Kansas, one heck of a big fish has been landed with the help of dinosaur researchers at the University of Kansas.

Name: Bonnerichthys. It measured close to 30 feet long and had an enormous mouth. And at the time of the great dinosaurs on land, it was gulping the tiniest of sea creatures.

Researchers, reporting in the Friday issue of the journal Science, say it provides the first definitive evidence that giant plankton-eating fishes similar in diet to today's baleen whales, basking sharks and manta rays plied the earth's waters during the Jurassic and Cretaceous periods.

"The fact that creatures of this kind were missing from the fossil record for hundreds of millions of years was always a mystery," Oxford University paleontologist Matt Friedman said in a release. "We used to think that the seas were free of big filter feeders during the age of the dinosaurs, but our discoveries reveal that a dynasty of giant fishes filled this ecological role in the ancient oceans for more than 100 million years."

The best fossils of the fishes were found in the chalk of western Kansas, in Logan County, with other fossilized remains coming from England and Japan.

"It's an interesting image to think of these things snorkeling around Kansas, sucking water," said Larry Martin, KU's curator of vertebrate paleontology.

The fish was named for the family of Marion Bonner whose finds, including this one, helped fill the natural history museums at the University of Kansas and the Sternberg Museum in Hays.

The fossils of Bonnerichthys, primarily the head and toothless jaw, had been at KU since the 1970s, but were only recently prepared in a way to create casts to help the researchers understand their ancient significance.

"Real discovery is not the moment you find something, it is the moment you figure out what you've found," Martin said.
Friedman led the research team that included Martin, as well as researchers from Fort Hays State University, University of Glasgow in Scotland, DePaul University in Chicago, Colorado's Triebold Paleontology Inc. and the Rocky Mountain Dinosaur Research Center.

"Once we had it prepared, we really realized what we had," Martin said. "That caused us to go back and look at other fishes in other collections. The ones in England had been lying around there for close to 150 years."

The fossils came from Logan County, originating between 172 million and 65 million years ago at a time when duck-billed dinosaurs and armored dinosaurs roamed the land.

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