World’s oldest mammal identified with teeth records from 225 years ago

The world’s oldest known mammal has been identified using dental records – predating what scientists previously thought was the first mammal to walk the Earth by millions of years – according to new research.

In the study, published in the peer-reviewed Journal of Anatomy on MondayBrazilian and British researchers from the Federal University of Rio Grande do Sul, London’s Natural History Museum and King’s College London confirmed that the Brasilodon quadrangularis was the earliest mammal with fossil records of the animal’s teeth sets.

The Brasilodon was a tiny, “shrew-like” animal that measured almost 8 inches long. Dental records for the mammal date back more than 225 million years – meaning the Barsilodon existed at the same time as some of the oldest dinosaurs, but 25 million years after the Permian-Triassic mass extinction, according to a Natural History Museum news release.