Oldest mammal ever to have walked the Earth lived 225 million years ago, says study
Shrew like animal
Fossil dental records have led to the identification of the world's oldest mammal, which predates the previously confirmed earliest mammal by about 20 million years, CNN reported. Researchers are excited about the new discovery as it can help shed light on the evolution of modern mammals.
Called Brasilodon quadrangularis, the animal was a small shrew-like creature, around 20 centimetres (8 inches) long, that walked the earth 225 million years ago. Researchers at the Natural History Museum in London, King's College London and the Federal University of Rio Grande do Sul in Porto Alegre made the discovery.
Fossils of hard tissues such as bones and teeth were used by scientists for the study since mammalian glands, which produce milk, have not been preserved in any fossils found to date.
Until now, the Morganucodon was thought to be the first mammal. As per records, it dated back around 205 million years. The Morganucodon had a small gerbil-like body and a long face similar to those of shrews or civets.
But now, the dental records in the study published Tuesday in the Journal of Anatomy date Brasilodon quadrangularis to 225 million years ago. This is 25 million years after the Permian-Triassic mass extinction event, which is the third and biggest mass extinction. This event led to the extinction of more than 90% of species in the ocean and 70% of land animals died out.
Brasilodon is the oldest extinct vertebrate with two successive sets of teeth -- baby teeth and one permanent set -- also known as a diphyodonty, the news release said.
(With inputs from agencies)
