News Paleontology

Early Mammal’s Jaw Lost Its Groove

By Sid Perkins

- More than 2 years ago

A tiny fossil skull found within 195-million-year-old Chinese sediments provides evidence that crucial features of mammal anatomy evolved more than 45 million years earlier than previously recognized.

An artist’s conception of Hadrocodium Wui and its skull, with a paperclip to provide a sense of scale for the 2-gram insectivore. Mark A. Klinger/CMNH

The well-preserved fossil shows several characteristics of mammals, says Zhe-Xi Luo, a vertebrate paleontologist at the Carnegie Museum of Natural History in Pittsburgh.