The earliest origin of human teeth

A new extinct reptile species reveals how our earliest ancestors changed their teeth to cope with environmental instability and became top carnivores about 300 million years ago

Researchers from the University of Bristol found that this evolutionary adaptation laid the foundation for the incisors, canines and molars that all mammals, including humans, have today.

Shashajaia is one of the most primitive members of the Sphenacodontodae class, which includes the famous Diplodocus, and mammal-like reptiles from the order Theropterus, which eventually evolved into mammals

Dr.

Shashajaia’s new teeth list shows that in the late Carboniferous, a period known for giant insects and global swamp rainforests, large, canine-like, differentiated teeth appeared in synaptic animals

By analyzing and comparing the tooth changes observed in Shashajaia with other synaptic animals, studies have shown that in the global climate change about 300 million years ago, the once prevalent Carboniferous wetlands were replaced by drier and more seasonal environments.

The study’s first author, Dr.

This new reptile is one of the oldest synaptic animals

Dr.

The site is located in an area known as the "Valley of the Gods" and is of great significance to paleontologists

Dr.

A Carboniferous synapsid with caniniform teeth and a reappraisal of mandibular size-shape heterodonty in the origin of mammals