145 million-year-old fossils of tiny rat-like creatures are found on Dorset’s Jurassic Coast

They walked the Jurassic Coast of Dorset around 145 million-years ago. 

Now scientists have discovered fossils of the oldest mammals related to mankind. 

Researchers have found two teeth from small, rat-like creatures that lived in the shadow of the dinosaurs, according to Daily Mail.

They are the earliest undisputed fossils of mammals belonging to the line that led to human beings.

 They are also the ancestors to most mammals alive today, including creatures as diverse as the blue whale and the pigmy shrew.

Dr Sweetman, a research fellow, identified the teeth but it was  undergraduate student, Grant Smith who made the discovery.

Dr Sweetman said: ‘Grant was sifting through small samples of earliest Cretaceous rocks collected on the coast as part of his undergraduate dissertation project in the hope of finding some interesting remains.

‘Quite unexpectedly he found not one but two quite remarkable teeth of a type never before seen from rocks of this age.

‘The teeth are of a type so highly evolved that I realised 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.

‘In the world of palaeontology there has been a lot of debate around a specimen, which is approximately 160 million years old.

‘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.’

Dr Sweetman believes the mammals were small, furry creatures and most likely nocturnal. 

One, a possible burrower, probably ate insects and the larger may have eaten plants as well. 

He said: ‘The teeth are of a highly advanced type that can pierce, cut and crush food.

‘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!’

The teeth were recovered from rocks exposed in cliffs ,which has given up thousands of iconic fossils. 

Mr Smith, said that he knew he was looking at something mammalian but didn’t realise he had discovered something quite so special.

His supervisor, Dave Martill, Professor of Palaeobiology, confirmed that they were mammalian, but suggested Dr Sweetman, a mammal expert should see them.

Professor Martill said: ‘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.

‘The Jurassic Coast is always unveiling fresh secrets and I’d like to think that similar discoveries will continue to be made right on our doorstep.’

N.H.Kh