“Y” is for Yuesthonyx

“Y” is for Yuesthonyx

Coming up with a Paleocene mammal that started with “Y” was another challenge. A big thanks to Dan Spivak (@danman222 on Twitter) for pointing this one out to me.

When Yuesthonyx was named, a new family of mammals was named as well, the Yuesethonychidae, was also named. This fossil mammal is known from the Henan province of China. As is frequently the case in paleontology, the fossils were collected in 1978, but the new species (and Family) wasn’t formally described and published until 2005.

Yuesthonyx is a Tillodont mammal, which once had a great distribution around the world. Its last surviving members lived in China and then went extinct in the Eocene.

The tillodonts are a group of mammals that were generally small to medium sized and may have looked somewhat rodent-like with large incisors. They were herbivorous mammals. They are part of the larger Order Cimolesta, which contained many different types of mammals, from hoofed herbivores, to insectivores, to carnivores. It’s possible that the Order Cimolesta may not be a true clade of mammals (meaning that they might not all share the same common ancestor).

The dentition of the tillodont Esthonyx. Notice the chisel-like second incisors (labeled I2).

Part of the Blogging from A to Z challenge

For 4-29-13

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