Researchers have confirmed that fossils discovered on southern England’s Jurassic Coast belonged humankind’s earliest known mammal ancestors.
Grant Smith, an undergraduate student at the University of Portsmouth, made the discovery while sifting through Cretaceous rocks from the Jurassic Coast for a dissertation project. Smith collected two teeth during his excavations that belonged to rat-like creatures 145 million years ago, during the time of the dinosaurs.
The teeth belonged to a species of mammals that are the earliest known ancestors of most mammals on Earth, including humans.
Smith worked with Dr. Steve Sweetman, a research fellow at Portsmouth, to examine the fossils and confirm the discovery.
Their findings were published in the journal Acta Palaeontologica Polonica.
Sweetman notes that the fossils are the oldest known to exist of our early mammalian ancestors.
“In the world of palaeontology there has been a lot of debate around a specimen found in China, which is approximately 160 million years old,” said Sweetman. “This was originally said to be of the same type as ours but recent studies have ruled this out. That being the case, our 145 million-year-old teeth are undoubtedly the earliest yet known from the line of mammals that lead to our own species.”
The teeth would have belonged to small, furry, and likely nocturnal creatures. The research team was able to determine the animal’s eating habits and even guess age based on the fossils.
“The teeth are of a highly advanced type that can pierce, cut and crush food,” Sweetman explained. “They are also very worn which suggests the animals to which they belonged lived to a good age for their species. No mean feat when you’re sharing your habitat with predatory dinosaurs.”
By Kay Vandette, Earth.com Staff Writer