These Lizards Mysteriously Survived the Asteroid Strike That Killed the Dinosaurs--and Their Descendants Are Still Alive

[Judi Lynn]

These Lizards Mysteriously Survived the Asteroid Strike That Killed the Dinosaurs—and Their Descendants Are Still Alive Today

Small and elusive night lizards probably persisted because they have slow metabolisms and like to hide out in rock crevices, a new study suggests

Sarah Kuta - Daily Correspondent
June 25, 2025 4:21 p.m.



Today's living night lizards—like Xantusia vigilis (pictured)—are descendants of a common ancestor that lived roughly 90 million years ago, well before the Chicxulub asteroid struck Earth 66 million years ago. Natalie McNear via Flickr under CC BY-NC 2.0


When the 7.5-mile-wide Chicxulub asteroid smashed into Earth 66 million years ago, it killed most living creatures within hundreds of miles of the impact site. In the chaotic aftermath of the strike, roughly 75 percent of all species worldwide went extinct, including the non-avian dinosaurs.

Yet, somehow, a group of lizards living near the collision point managed to survive not only the initial disaster, but also the ensuing fallout, as researchers report Wednesday in Biology Letters. This makes the reptiles “unique among living families of terrestrial vertebrates,” as they are the only one known to have survived this mass extinction event while living “in close proximity to the impact location,” the team writes in the paper.

Night lizards (Xantusiidae) are a family of small, elusive reptiles that spend most of their time hiding in crevices and under rocks. Today, they’re found in Mexico, Central America, Cuba, California and the southwestern United States.Researchers knew the night lizard lineage has been around a long time—likely tens of millions of years. But they wanted to get a more precise understanding of the group’s timeline.

Using previously published DNA sequence data, scientists created an evolutionary family tree for night lizards. By studying their mutations over time, the team was able to estimate when the lizards evolved.

More:
https://www.smithsonianmag.com/smart-news/these-lizards-mysteriously-survived-the-asteroid-strike-that-killed-the-dinosaursand-their-descendants-are-still-alive-today-180986879/

[Bayard]

1. Wonder how they survived the nuclear winter the asteroid collision caused?