The family Xantusidae It includes thirty species, and you are forgiven if you do not know them: they are small lizards who live on the American continent, very difficult to meet and practically unknown to non -professionals.
Yet now a study published on Biology Letters He shows that these lizards are more interesting (and resistant) than we thought: they are unique among the vertebrates who lived near the place where the asteroid Chicxulub falls, the one that extinct the dinosaurs, because Not only did they survive, but they never even changed the house.
Lizards and asteroids. In English, family lizards Xantusidae they are called “night lizard“, Night lizards, despite having actually daytime habits: the name derives from the fact that they are so reserved that for centuries it was thought that they were active only at night, in fact. In reality they were only good at hiding: Long a few centimeters, they live in narrow and well protected places, such as cracks in the rocks or under the fallen trunks. There are only three genres, which all live between North and Central America.
Including the Gulf of Mexico, where 66 million years ago an asteroid fell to the ground, causing a series of catastrophes that led to themass extinction of the Cretaceous: the famous KT event, which led, among other things, to the information of the dinosaurs. The Yale University team who studied lizards was able to ascertain that the Xantusidae family appeared about 90 million years ago, and since then its members have always lived in the same place.
This is our home! Not even the impact of the asteroid managed to make these lizards dislocate from their shelters: perhaps thanks to theirs very slow metabolismwhich allowed them to fast for long periods, survived the impact of Chicxulub and its consequences, a company that succeeded very few species among those who lived in the surroundings of the future crater (and very few in general on the planet). Unlike the other locals, however, the “night lizards” have never gone, and still today They are endemic of Mexico And especially of the Yucatan peninsula.
The study also reconstructed the entire genetic history of the family, discovering that Two different groups survived the impact: from one of these then the genres were born Xantusiawhich lives in the south of the United States and Mexico, e Lepidophymawhich has a more moved area to the north; on the other hand, the third kind of Xantusidae was born, Cricosaurawho lives exclusively in Cuba.
In other words, All modern night lizards derive from those that survived the impact of meteoriteand who did not want to abandon their house even in front of the apocalypse.
