Palaeontologist on Thursday revealed in journal 'Current Biology' a small piece of bumpy fossil was found in Oklahoma caves, which is the oldest known patch of preserved skin.
An amateur chanced upon the skin fossil while working in the Richards spur limestone cave system, which is a well known fossil site in Oklahoma. He donated it to researchers in 2018.
This piece of skin, as tiny as a human fingernail, is about 289 million years old and dates back to the Permian period.
The Permian period was the time when the earth's continents formed one huge supercontinent which was surrounded by a global ocean.
Due to the generally dry and warm climate of the Permian period, early reptiles could make the transition from semiaquatic to completely land-based lifestyle.