Fossils show ancient primates had grooming claws as well as nails

June 20, 2018 by Natalie Van Hoose, University of Florida



Lemurs, lorises and galagoes have nails on most digits and grooming claws on their second toes, as seen on the feet of two greater slow lorises, Nycticebus coucang, in the Florida Museum mammals collection. Credit: Florida Museum/ Kristen Grace


Humans and other primates are outliers among mammals for having nails instead of claws. But how, when and why we transitioned from claws to nails has been an evolutionary head-scratcher.

Now, new fossil evidence shows that ancient primates—including one of the oldest known, Teilhardina brandti—had specialized grooming claws as well as nails. The findings overturn the prevailing assumption that the earliest primates had nails on all their digits and suggest the transition from claws to nails was more complex than previously thought.

"We had just assumed nails all evolved once from a common ancestor, and in fact, it's much more complicated than that," said Jonathan Bloch, study co-author and Florida Museum of Natural History curator of vertebrate paleontology at the University of Florida.

The findings are scheduled to be published today in the Journal of Human Evolution.

Read more at: https://phys.org/news/2018-06-fossils-ancient-primates-grooming-claws.html#jCp