Science

US researchers discover 'Shieldcroc,' dating back 95 million years

MU assistant professor Casey Holliday nicknamed Aegisuchus witmeri Shieldcroc because of its thick skinned shield.

MU assistant professor Casey Holliday nicknamed Aegisuchus witmeri Shieldcroc because of its thick skinned shield.  (University of Missouri)

A new species of prehistoric crocodile that dates back 95 million years ago has been identified by a University of Missouri researcher.

The extinct creature, nicknamed “Shieldcroc” due to a thick-skinned shield on its head, is an ancestor of today’s crocodiles. Its discovery provides scientists with additional information about the evolution of crocodiles and how scientists can gain insight into ways to protect the species’ environment and help prevent extinction, according to the University of Missouri website.

“Aegisuchus witmeri or ‘Shieldcroc’ is the earliest ancestor of our modern crocodiles to be found in Africa,” said Casey Holliday, co-researcher and assistant professor of anatomy in the MU School of Medicine. “Along with other discoveries, we are finding that crocodile ancestors are far more diverse than scientists previously realized.”

Shieldcroc is the newest discovery of crocodile species dating to the Late Cretaceous period, approximately 95 million years ago.

According to the university website, Holliday identified Shieldcroc by studying a fossilized partial skull specimen, which was discovered in Morocco and held by the Royal Ontario Museum of Toronto for several years before Holliday analyzed it.

Holliday determined, by studying blood vessel scarring on the bone, that the crocodile would have had a structure on top of its head, resembling a shield. The dents and bumps on the bone indicate veins delivered blood to a circular mound of skin, something never before seen in a crocodile. He said the shield was likely used as a display structure to attract mates and intimidate enemies and possibly as a thermo-regulator to control the temperature of the animal’s head.

The Shieldcroc fossil studied by Holliday and Nick Gardner, an undergraduate researcher at Marshall University, is being returned to the Royal Ontario Museum, where it will be put on display later this year.

Click for more on this story and to see the video of the ‘Shieldcroc’ skull specimen at the University of Missouri website