Paleontologists have restored the appearance of a mysterious prehistoric creature, which is a dead-end branch that developed in parallel with dinosaurs. Analysis of the remains of a small reptile called Drepanosaurus showed that it had massive claws on its forepaws. Probably, a formidable weapon was necessary for the animal to open the bark on trees and search for insects under it.
Outwardly, the reptile that lived in the United States about 212 million years ago resembles a hybrid of a chameleon and an anteater. Despite the apparent resemblance to lizards, the animal does not belong to any of the modern groups of reptiles. The drepanosaur lineage shares common ancestors with dinosaurs, lizards and crocodiles, and has been known to this day from the only poorly preserved remains found in northern Italy over 30 years ago.
A new find from the Ghost Ranch quarry in the US state of New Mexico was able to tell much more about the extinct creatures. The animal was about the size of a cat and most likely lived in trees.
A team of researchers led by Yale University's Adam Pritchard performed a 3D reconstruction of the Drepanosaurus forelimbs based on CT scans of dozens of harvested bones, many of which were shattered.
One of the most surprising features of the Drepanosaurus is the structure of its forelimbs. These body parts in quadrupeds are known for their versatility. They are suitable for walking, digging, flying and swimming. At the same time, the skeleton of the forelimbs has hardly changed over 375 million years of evolutionary development.
In four-legged animals, the forearm consists of two elongated radius and ulna bones running parallel to the elbow, which in turn connect to a series of shorter wrist bones. And in Drepanosaurus, the ulna is flat and curved in the shape of a crescent. In addition, the bones of the wrist connected to it are much longer than the rest and, in fact, even exceed the radius of the radius. And all this was necessary in order for the claw at the end of the index finger to be a really powerful tool, scientists say.
“The junction of the bones suggests that the enlarged claws of the drepanosaurs were needed to ravage insect nests,” Pritchard said in a university press release. “A hand like that could tear them apart with ease. Its potential motor skills resemble the behavior of anteaters, which also feed on insects.
A detailed description of the reptile is presented in an article published in Current Biology.
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It is interesting that the unique body structure of the ancient reptile was not transmitted to any other animals, that is, it was the so-called dead-end branch of development. In anteaters, a similar anatomical feature developed much later, one might say, "from scratch", and is determined by the habitat and food interest.
Work in New Mexico continues, and scientists are hoping to find new samples of amazing animals that will give rise to fresh evolutionary discoveries.