A Pair of Lizard ‘Kings’ from the Old, Old West

A modern iguana, left, and two blocks (right) containing the holotype of Microteras borealis. The holotype consists of a portion of the snout (top) and the braincase (bottom). Although not an iguanan, Microteras borealis is one of the oldest examples of the crown lizard group that includes all living lizards. (Courtesy of the Yale Peabody Museum of Natural History)
December 2, 2022

Yale researchers have identified the oldest-known, definitive members of the lizard crown group that includes all living lizards and their closest extinct relatives. The two new species, Eoscincus ornatus and Microteras borealis, fill important gaps in the fossil record and offer tantalizing clues about the complexity and geographic distribution of lizard evolution.

The new lizard “kings” are described in a study published in Nature Communications. “This helps us time out the ages of the major living lizard and snake groups, as well as when their key anatomical features originated,” said Chase Brownstein, first author of the study. Brownstein, a Yale senior, collaborated on the study with Yale paleontologists (YIBS Affiliates), Jacques Gauthier and Bhart-Anjan S. Bhullar

Gauthier is a professor of Earth and planetary sciences in Yale’s Faculty of Arts and Science and curator at the Yale Peabody Museum of Natural History. Bhullar is an associate professor of Earth & planetary sciences and an associate curator at the Peabody Museum. Funding for the research came, in part, from the National Science Foundation and the Yale Institute for Biospheric Studies (YIBS). For more information, click here for an article published by YaleNews

News & Updates

Close-up of a male greater sage-grouse ‘strut’ display

Study led by YIBS Faculty Affiliate Richard Prum's lab reveals mating tip for bird species: You should be dancing

May 30, 2025
When it comes to impressing the ladies, greater sage-grouse males know that smooth dance moves trump combative posturing. Indeed, new Yale research into these prairie-...
A cactus wren

Even birds can’t outfly climate change

May 28, 2025
As rising global temperatures alter ecosystems worldwide, animal species usually have two choices: adapt to changing local conditions or flee to a cooler clime. Ecologists...
Thomas Near and others have discovered two darter species — the Gurley Darter and the Birmingham Darter — in the Mobile River system in central Alabama.

YIBS Faculty Affiliate Thomas Near and others find two new fish species in Alabama streams — and they’re already imperiled

April 29, 2025
Yale researchers have discovered two new species of darter — small, colorful freshwater fishes — inhabiting short stretches of creeks and streams in central Alabama.  And...