A study of the family history of primates whose last ancestors landed in North America from distant treetops is gradually revealed through a comparison of teeth and mandibles that are thousands of miles apart.
Humanity arrived in the New World with many sad histories of extinction, including North America. However, at least in this case, we do not have much responsibility for the members of our own order. This is not because no primates have ever been to North America, but because they have been extinct for a very long time.
After a difficult journey, the monkeys crossed the Darién Pass and thrived in the rainforests of Panama and Costa Rica. However, the climate in northern Mexico is less friendly to them, and as far as we know, they never settled in the United States today. Before that, however, an early primate had made its home in the forests of North America, and its name was Ekgmowechashala, which literally translates to "kitten people" in Sioux language. New research helps explain where it came from.
Ekgmowechashala is a relatively small species, probably weighing only about 2 kilograms (5 pounds). Initially only one species of teeth were found, while they were mainly found in the Great Plains region, and these findings led to the idea that Ekgmowechashala may be similar to raccoons in some way. At least until humans open the trash can, the raccoon-like role has never changed. Another species associated with it has been found in Oregon.
However, none of this can determine the right place to insert these little ones into the tree of the broader primate family. That was until the discovery of the ancient owl-toothed beast, a species derived from Chinese fossils. Its name means "ancient wanderer" and does not describe its eating Xi.
According to Kathleen Rust, a PhD student at the University of Kansas, the Archaeodont is a close relative of Ekgmowechashala, revealing that both are part of an expansion that originated in South Asia.
"[Ekgmowechashala] has been a subject of controversy and controversy about its belonging to the mammalian evolutionary tree due to its unique morphology and the mere presence of tooth remains," Rust said in a statement. ”
"Most people tend to think of it as a primate. However, the timing and morphology of this primate's appearance on the North American fossil record are very anomalous. Within a four-million-year cycle after the extinction of all other North American primates about 34 million years ago, he suddenly appeared on the fossil record of the Great Plains. ”
The first fossil skeletons of the Australopithecus were collected in Guangxi, China, by Professor Chris Beard, Rust's PhD supervisor. Although nearly 30 years have passed since Beard's discovery, the kinship of two primates around the world was finally revealed when the study was published. Beard said he recognized the connection when he discovered the mandibles of the first Australopithecus aloft.
"When I picked up my mandible, I immediately realized, 'Wow, this is it. Beard said. "It doesn't take long, and we don't have to do all sorts of detailed analyses to know it's it. It took longer to prove this to the world, but Rust and Beard are confident that the similarity between the maxillary molars they found in Guangxi, China, and the Ekgmowechashala specimen from the University of Kansas will earn them recognition.
Rust and Beard believe that Ekgmowechashala's ancestors crossed the Bering Strait millions of years before humans and settled in the empty forests of primates in the Rocky Mountains. This is inconceivable for a tropical rainforest animal, and the glacial terrestrial connection that took place during this time period briefly provided it with such an opportunity.
In the Early Miocene, Ekgmowechashala fared well, and North America was a warmer, wetter place, giving it stormy rainforests. As the world gets colder, the environment changes, and there is no place for it to survive in such a northern place.
Primates arrived in North America 56 million years ago and evolved shortly after a long time into obscurity. After about 20 million years of differentiation, an earlier round of cold, dry weather exterminated them, however some believe that Ekgmowechashala survived this extinction. However, according to new research, it's more like an immigrant.
The study was published in the journal Human Evolution, which is freely available.