Fossil Tail From Jurassic Could Shed Light on Crocodiles’ Family Tree

Friday, May 18, 2018

Fossil Tail, Jurassic Crocodile Family Tree

A fossil tail was discovered by paleontologists, who believe it could be the missing link in the evolution of crocodiles.

Ancient crocodiles in the Jurassic period (200-145 million years ago) were split into two groups. One group of crocodiles had an armored skin – like dinosaurs, and used their limbs to walk. The second group looked more like a dolphin: they had tail fins, flippers and no armors like the land group.

The fossil is 180 million-years-old, and researchers believe that it belonged to an intermediary species of the two groups. Mark Young, with the University of Edinburgh’s School of GeoSciences, explains their findings:

“This fossil provides a unique insight into how crocodiles began evolving into dolphin and killer whale-like forms more than 180 million years ago.”

The tail fossil points towards a crocodile that had both the tail fin and the armor, meaning that crocodiles were highly diverse in the Jurassic era.

Young and his colleagues at the university have discovered the tail in 1996. They dug it up in a mountain in Hungary and called it Magyarosuchus fitosi – after Attila Fitos.

Not So Different from Their 30 Million-Years-Old Ancestors

Young and his colleagues published the study in the journal PeerJ. Their study points out that the fossil belongs to a species of crocodiles that is different from the other ones. The tail contained a weird looking vertebra, writes the report:

“The unique combination of retaining heavy dorsal and ventral armor, while having a slight hypocercal tail, on the other hand, highlights the mosaic manner of marine adaptations in Metriorhynchoidea.”

Evan Whiting is a doctoral student at the University of Minnesota and studies crocodiles. He explains why discovering a new species of crocodiles back in the past is so rare:

“If we could step back in time 8 million years, you’d basically see the same animal crawling around then as you would see today in the Southeast. Even 30 million years ago, they didn’t look much different.”