What Kind Of Lizard Did You Find In Wyoming?

Jul 2, 2015

A photograph of a living relative of the new fossil. This is Basiliscus, a Jesus Lizard that was photographed at La Quinta Balcarcel, Guatemala; the fossil lizard may have looked similar to this when it was alive.
Credit Ana M. Balcarcel

When you think of a Jesus lizard you probably think of the rainforest creature: green crested with big floppy feet zipping across the surface of water.

Now, a new skull fossil shows that a very close relative of that lizard lived in Wyoming 50 million years ago. Anatomy professor Jack Conrad from the New York Institute of Technology just released a paper on the discovery. 

“The fact that we’re finding one in Wyoming when the earth was nine degrees Celsius warmer, is just further evidence that Wyoming used to be a tropical landscape,” Conrad says. “It was basically like a rain forest with fresh water rivers and lakes. You had crocodiles, you had big mammalian predators.”

An image from the CT scan of the specimen from the left side view
Credit Jack Conrad

Conrad says the fact that the Jesus lizards once lived this far north shows climate fluctuations do cause species to expand and contract their territory significantly. He says warming temperatures could mean the return of tropical vipers or malaria into regions like Colorado, New Mexico and Wyoming.

He says, even though only the skull was found, it’s clearly a close relative to the Jesus lizard of South America.

“This is a full blown member of the group, not like some distant cousin. It’s as close to the living species as a lion is to a tiger. And so it really demonstrates that this group used to be much more wide spread.”

Conrad says Wyoming is a great place to study this time period known as the Eocene Epoch when large mammals and lizards roamed. He says in Wyoming, fossils like this one are easier to find since they often protrude right out of the ground, as this one did when it was discovered in Uinta County.