Thrinaxodon

Our ancestor in the Mesozoic era

The reptile Thrinaxodon laid eggs, like all reptiles, but had some features that are usually only found in mammals: whiskers, fangs, molars, and fur.

It is assumed that the females had milk-producing mammary glands, and the newly hatched young could thus be fed by the mother directly in the nest. The mother no longer had to leave her young in the burrow to search for food, which was an enormous advantage over other reptile species.

So, mammary glands significantly increased the young's chances of survival. On the other hand, the number of newborns was reduced because the mother could only produce a limited amount of milk.

In Thrinaxodon, the mammal-like characteristics are so present that the reptile is described by scientists as a missing link between reptile and mammal. This makes Thrinaxodon a distant ancestor of humans.