Night Lizards Survived ⁢Dinosaur Asteroid Strike, Study Finds

‍ Updated June ⁤25, 2025

Night lizards,‍ small reptiles, not only ‌lived through the asteroid strike that decimated the ​dinosaurs ‍66 million years ago, but ‌they continue to inhabit the same region today,⁣ according⁤ to⁤ new research.‍ The study pinpoints these lizards as the only⁤ group of land vertebrates known to have survived so‌ close to the ⁢impact zone and still maintain⁣ a presence there.

The cataclysmic asteroid,striking what is now Mexico’s Yucatán Peninsula,triggered the ​Cretaceous-Paleogene (K-Pg) mass extinction.⁢ This ⁣event wiped out approximately 75% of Earth’s species. ⁤Despite the widespread devastation, two lineages of night lizards managed​ to persist.

Chase Brownstein, a doctoral ‌candidate⁤ at‌ Yale University and lead author​ of the study, said the ‍lizards likely lived “all around the margin of the asteroid impact.”

The findings were published Wednesday in the journal ⁢ Biology Letters.

The survival of these creatures remains‌ something ‍of a ⁤mystery. Brownstein ‌speculated that their slow metabolisms may have played a role,reducing‌ their need for frequent meals.

These secretive lizards, often just a few ​inches⁤ long, typically reside in ​microhabitats such as rock crevices, dense vegetation, or under bark and logs.

Previous​ research suggested⁣ that⁣ the “crown” ⁢group of night lizards-containing the most recent common ancestor of​ all living night lizards-existed during the dinosaur ⁣era.The new study tested this hypothesis by reconstructing the ancestry of the three living night lizard genera: Lepidophyma, Xantusia, ‌and Cricosaura. Researchers‌ used molecular clock dating, analyzing ⁢DNA mutations to estimate when⁤ the lizards evolved.

The ​analysis⁣ revealed that the most recent common ancestor ⁤of ​living night lizards emerged roughly 90 million years ago during the⁣ Cretaceous period. This indicates ⁣that night lizards have inhabited North and Central America since that time,predating the asteroid impact.

The research ⁤indicates that two⁣ night lizard lineages survived the asteroid’s impact. One lineage evolved into xantusia, found from the southwestern U.S. into ⁤Mexico, and Lepidophyma, present across ‌parts of North and Central‍ America. The second lineage led to Cricosaura and its sole ⁤species, the‍ Cuban night lizard (Cricosaura typica), in Cuba.

While night lizards are not the only animals to​ survive the K-Pg extinction-avian dinosaurs (birds) and some mammals ​also made it through-they⁢ are the only known surviving group of terrestrial ‌vertebrates⁢ that have remained ‌endemic to ​North and Central America since the asteroid strike.

What’s next

Brownstein suggests​ that further research‌ may reveal similar survival stories among other turtle and ​lizard lineages in the region, offering more insights ⁣into how life persisted through one of Earth’s ⁤most catastrophic events.