Feb 09, 2016 09:39 AM EST By Russell Westerholm, UniversityHerald Reporter

A team of researchers identified new species of a rare, ancient fish genus that existed just less than 100 million years ago during the Cretaceous Period.

Published in the journal Cretaceous Research, the new study details two new species of the Rhinconichthys fish that fed on plankton. The original specimen was found in England, but the new fossils appeared in Colorado.

"I was in a team that named Rhinconichthys in 2010, which was based on a single species from England, but we had no idea back then that the genus was so diverse and so globally distributed," study co-author Kenshu Shimada, a paleobiologist at DePaul University, said in a press release.

Rhinconichthys are a descendant of the fish group known as pachycormids, which are the largest bony fish on record. The Rhinconichthys was about six-and-a-half feet in length, but its defining characteristic was a strange jaw that allowed it to open its mouth abnormally wide.

"Based on our new study, we now have three different species of Rhinconichthys from three separate regions of the globe, each represented by a single skull," Shimada said. "This tells just how little we still know about the biodiversity of organisms through the Earth's history. It's really mindboggling."

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