A group of paleontologists from the University of Portsmouth has discovered two new species of mammals that lived 145 million years ago in what is now Dorset county, southern England.
The new fossil mammals, named Durlstotherium newmani and Durlstodon ensomi, lived alongside dinosaurs.
They were small, furry creatures and most likely nocturnal.
Durlstotherium newmani, a possible burrower, probably ate insects and Durlstodon ensomi may have eaten plants as well.
Professor Dave Martill led the research team, which reports its findings in a paper published this week in the journal Acta Palaeontologica Polonica.
The fossil remains (two teeth) of Durlstotherium newmani and Durlstodon ensomi were recovered from rocks exposed in cliffs near Swanage in Dorset, southern England.
“The teeth are of a type so highly evolved that I realized straight away I was looking at remains of Early Cretaceous mammals that more closely resembled those that lived during the latest Cretaceous — some 60 million years later in geological history,” said co-author Dr. Steve Sweetman, a research fellow at the University of Portsmouth.
“In the world of paleontology there has been a lot of debate around a specimen found in China, which is approximately 160 million years old,” he added.
“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.”
“I knew I was looking at something mammalian but didn’t realize I had discovered something quite so special,” said co-author Grant Smith, an undergraduate student at the University of Portsmouth.
Professor Martill added: “we looked at them with a microscope but despite over 30 years’ experience these teeth looked very different and we decided we needed to bring in a third pair of eyes and more expertise in the field in the form of our colleague, Dr. Sweetman.”
“Steve made the connection immediately, but what I’m most pleased about is that a student who is a complete beginner was able to make a remarkable scientific discovery in paleontology and see his discovery and his name published in a scientific paper.”
Steven C. Sweetman et al. Highly derived eutherian mammals from the earliest Cretaceous of southern Britain. Acta Palaeontologica Polonica, published online November 7, 2017; doi: 10.4202/app.00408.2017