Paleontologists found the evidence of milk teeth from the jaw of a juvenile Wareolestes rex fossil that was found from the Skye Island, Scotland. The mammal specimen was about 165 million years old which indicates, the species used to roam around the Jurassic age. Until today, researchers found two specimens from Scotland and this one is the third.

The specimen was found by a team of researchers from National Museums Scotland, the University of Edinburgh and the University of Oxford during the field work in 2015. The Scotsman has reported that Wareolestes rex is the only species having a few single molar teeth that were unearthed from England. The mammal species has evolved between 252 and 66 million years ago and it is the first mammal species that lived along with the Triassic, Jurassic, and Cretaceous period.

The newly discovered Jurassic aged fossil includes a complete structure of jaw with teeth inside. Most important fact is that some teeth was still inside the gum and not yet grown. Researchers described that the properties of their teeth were just like humans and other mammals of today, Milk teeth sets used to get replaced by the permanent sets.

However, the pattern of producing milk was quite different from the modern mammal species. According to BBC, in Jurassic period most of the mammals didn’t have nipples or breast tissues as the milk was secreted from the mother’s skin. Same kind of milk delivery feature could be seen in today’s platypus.

Ph.D. student at the University of Edinburgh and National Museums Scotland, Elsa Panciroli said,“Wareolestes would have cared for its young, which is a behavior we associate with modern mammals. Tooth replacement like this tells us this early mammal fed on milk provided by the parent until it grew to adult size”. She also explained that the size of Jurassic mammal species was not more than the size of a guinea pig.