A yellow-spelled Tropical Night Lizard (Lepidophyma flavimaculatum)
Dante Phenol / Science Photo Library
A small, secret group of lizards still with today is the only terrestrial vertebrates saved in the neighborhood of Chicxulug asteiid coldisionwhich leads the extinction of non-avian dinosaurs.
It has been known that the nights of Xantusiid nights are an ancient generation in ten million years. but Chase Brownstein At Yale University and his companions suspect that the group may actually arise than previously thought: during the Cretaceous, which ended about 66 million years ago.
Cretaceous finish is marked by a giant asteroid strike in the Mexican Yucatán Peninsula neighborhood, leaving a 150 kilometers of 150 kilometers width by most animal species in the world.
Today, the lizards of the night – a wrong person, because they are not real nocturnal – still found in Cuba, Central America and southwest in the US.
Brownntein and his team used to publish DNA Sequence Data for Xantusiids to create a wooden evolutionary for the group. They combine it with a skeleton anatomy across the lizards of living and fossil, allowing the team to see how many lines are and estimates how many children’s ancestral ancestors are.
They knew that the newest common ancestor of living Xantusiids emerged deep inside Cretacaceo, more than 93 million years ago, and there might be straps with one or two children.
“I think it’s possible that these old populations are as close to or closer to the place of effect than today,” Brownstein said. “Almost as if the distribution of Xantusiide Sketchs is a circle around the effect of the site.”
Based on fossil evidence, unlikely that ancient lizards at night also remember the region later, as Brownstein.
“We learned from our revival that the common ancestor of the association of species that almost settled in North America, where the record of Xantusiids was a bit of the effect,” he said.
Many species of lizards at night live in stone holes and their slow metabolism is compared to other survivors of mass, such as turtles and crocodiles. “It is, perhaps, let them face the impact effect and it immediately,” says Brownstein.
Nathan Lo At the University of Sydney says lizards are unique. “They live in the region around the side effect of the asteroid, (yet) they have made a living, even if the asteroid will be wife to the organizers in the impact.”
They manage it even though there are no many usual attributes that we expect to see the survivors of mass developments. “Species associated with the events of extinction are those smaller in size, can be copied immediately and have many geographical scope,” Lo said. “But these lizards usually change slowly and seems to be very small in order.”
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