Study of fossils shows ancient crocodiles were a varied group

BRISTOL, England, Sept. 11 (UPI) -- Ancient relatives of crocodiles were extremely diverse and inhabited varied ecosystems to survive in a dinosaur-dominated world, British paleontologists say.

While most modern crocodiles live in freshwater habitats and feed on mammals and fish, their forbears filled a number of ecological niches, the researchers said, with some built for running around on land to hunt like dogs and others adapting to life in the open ocean, imitating the feeding behavior of today's killer whales.

A study published in the journal Proceedings of the Royal Society B describes how analysis of fossil jaws of ancient crocodiles shows how they evolved to survive in vastly different environments while living alongside the dinosaurs from 235 million to 65 million years ago.

"The ancestors of today's crocodiles have a fascinating history that is relatively unknown compared to their dinosaur counterparts," Toms Stubbs of the University of Bristol said. "They were very different creatures to the ones we are familiar with today, much more diverse and, as this research shows, their ability to adapt was quite remarkable."

Comparison of lower jaws of a number of ancient crocodiles showed the group evolved a great variety of lower jaw shapes as they adapted to a diverse range of feeding behaviors and terrestrial environments alongside the dinosaurs.

"They evolved lifestyles and feeding ecologies unlike anything seen today," Stubbs said.