Mammals that lived alongside dinosaurs grew more slowly and lived longer than they do today, analysis of fossils found on the Isle of Skye has revealed. A team led by researchers at National Museums Scotland analysed the fossils of an adult and a juvenile Krusatodon kirtlingtonensis, a mouse-sized mammal that lived about 166 million years ago, which were found on the island. Advertisement Advertisement Sign up to our Scotsman Rural News - A weekly of the Hay's Way tour of Scotland emailed direct to you.
Thank you for signing up! Did you know with a Digital Subscription to The Scotsman, you can get unlimited access to the website including our premium content, as well as benefiting from fewer ads, loyalty rewards and much more. They used X-ray imaging to count growth rings on the animals’ teeth, and found that the adult was about seven years old and the juvenile was between one and two years old – and still in the process of replacing its baby teeth. Today small mammals have significantly shorter lifespans, some living as little as 12 months, and they mature quickly, losing their baby teeth and weaning within months of birth.
This indicates, the researchers say in a paper published in the journal Nature, that a fundamental shift in the growth patterns and life expectancy of mammals must have taken place during or after the middle Jurassic period (roughly 174 to 161 million years ago). Dr Elsa Panciroli, lead author and associate researcher of palaeobiology at National Muse.