The earliest known evidence of hair is whiskers on therapsids, which were mammal-like reptiles that lived around 290 million years ago. Therapsids are considered the ancestors of modern mammals.
Hair is a defining biological characteristic of all mammals. However, some species have evolved to have so little hair that they appear nearly naked.
There is an explanation video available below.
Contributions ({{ comment_count }})
Please wait...
Modal title
Report
Block User
{{ feedback_modal_data.title }}