Survivors of the Apocalypse: These Lizards Survived the Planet’s Deadliest Impact

An asteroid strike 66 million years ago triggered the Cretaceous-Paleogene extinction, which wiped out the dinosaurs, along with about three-quarters of the Earth’s animal species. A new Yale University study has found that a group of lizards were among the unlikely survivors. These small reptiles were the ancestors of today’s xantusiid night lizards. They survived, despite the fact that they lived in the Yucatan Peninsula, the exact location of the asteroid impact. Details of the fascinating study are published in Biology Letters.

Because night lizards have only one to two young at a time, this new research challenges the assumption that producing large numbers of offspring is key to surviving mass extinction. Despite small litter sizes, fossil and genetic evidence indicate that at least two lineages lived through the catastrophic event. Scientists used a time-calibrated evolutionary tree built with nuclear DNA and fossil records to trace their history back roughly 92 million years. Results showed they were well established in North and Central America before the asteroid struck.

This slideshow will cover several aspects of night lizards, including their specialized microhabitats, which may have offered much needed protection in the aftermath of the collision. We’ll discuss the unpredictability of extinction dynamics and how endurance through extinction events is more complex than scientists once believed. Lastly, we’ll reveal the power of combining modern genetic databases with paleontological evidence to uncover evolutionary secrets.

Night Lizards: Ancient Survivors

©Jiri Vlach/Shutterstock.com” data-src=https://s.yimg.com/ny/api/res/1.2/j3JLxIoK43U.vGKXTDvFYA–/YXBwaWQ9aGlnaGxhbmRlcjt3PTEyNDI7aD04Mjg-/https://media.zenfs.com/en/a_z_animals_articles_974/9c88fc9e46e7fe5153c976338c526aed>

• Night lizards are small reptiles that survived the asteroid impact 66 million years ago near the Yucatan Peninsula.

• Despite their name, night lizards are mostly active during the day and at twilight.

• They belong to a species-poor lineage with anatomy that has changed little over millions of years.

Unique Survival Story

• Night lizards lived within the blast radius of the asteroid yet persisted through the Cretaceous–Paleogene extinction event.

• Unlike many survivors, they have small litter sizes of only one or two offspring.

• Their survival challenges the idea that producing many young is always the best strategy during mass extinctions.

Habitat and Distribution

• Night lizards inhabit microhabitats like rock crevices or decaying logs with unique environmental properties.

• They have been native to North and Central America since the Late Cretaceous, about 92 million years ago.

• These environments may have offered protection from extreme conditions during the extinction event.

Scientific Research

• Researchers used a method called Bayesian tip-dating to study night lizard evolution using DNA and fossil data.

• Nuclear DNA was analyzed instead of mitochondrial DNA to avoid inflated divergence time estimates.

• Findings suggest at least two night lizard lineages survived the asteroid impact.

Modern Significance

• Night lizards continue to intrigue scientists for their evolutionary resilience and ecological specialization.

• Their story highlights that survival after mass extinctions may depend on more factors than previously thought.

• Studies of night lizards benefit from public DNA databases like GenBank, which provide valuable genetic data.

The post Survivors of the Apocalypse: These Lizards Survived the Planet’s Deadliest Impact appeared first on A-Z Animals.