Extinct Reptile That Lived Among Dinosaurs Unearthed in Badlands of Wyoming

by Caitlin Berard

The Badlands are known for their abundance of fossilized plants and animals. Every year, scientists and visitors alike discover everything from horses to dinosaurs to prehistoric pigs among the ancient rock and soil. One of the most recent finds, a now-extinct reptile, was particularly exciting for researchers, as it helps to complete the evolutionary puzzle for modern-day lizards and snakes.

The reptile, which lived among the dinosaurs 150 million years ago, is an ancestor of New Zealand’s tuatara, the last surviving member of an order of animals originating over 250 million years ago.

The difference, however, is that while the tuatara is a massive reptile, measuring over 30 inches from nose to tail-tip, the fossilized reptile could fit in the palm of your hand. Named Opisthiamimus gregori, the ancient reptile was only about 6 inches in length. Researchers discovered its fossilized remains entombed in rive rocks dating back to the Late Jurassic period.

In an interview with Newsweek, Dr. Matthew Carrano from the Smithsonian Institution in Washington D.C. detailed the significance of the find.

“What’s important about the Tuatara is it represents this enormous evolutionary story that we are lucky enough to catch in what is likely its closing act,” Carrano explained. He then added that “even though it looks like a relatively simple lizard, it embodies an entire evolutionary epic going back more than 200 million years.”

Extinct Reptile Sent to Smithsonian Museum for Study

Since its discovery, the Opisthiamimus gregori has been added to the Smithsonian Museum’s collection of fossilized creatures. There, researchers will continue to study the extinct reptile in hopes of learning more about the Rhynchocephalian order and why the tuatara is its last remaining member.

“These animals may have disappeared partly because of competition from lizards,” Carrano said. “But perhaps also due to global shifts in climate and changing habitats.”

“It is fascinating when you have the dominance of one group giving way to another group over evolutionary time,” he continued. “And we still need more evidence to explain exactly what happened. Fossils like this one are how we will put it together.”

To make the fossilized reptile even more fascinating, the Opisthiamimus is almost entirely complete. The only parts missing are the tail and portions of the hind legs.

This is particularly rare in such a small animal because their tiny bones typically don’t make it to the fossilization process. Because of this, scientists primarily recognize members of its order by their jaws and teeth, not their entire body.

“Such a complete specimen has huge potential for making comparisons with fossils collected in the future,” researcher David DeMar explained. “And for identifying or reclassifying specimens already sitting in a museum drawer somewhere.”

“With the 3D models we have, at some point, we could also do studies that use software to look at this critter’s jaw mechanics.”