Cenomanian

And one of these groups that actually give snakes a surprisingly good run or slither for their money are something known as skinks.

This is a family of lizards that comprise over 1,500 species today, and first appeared in the Cenomanian.

It was the skinks alone who would on multiple occasions lose their limbs and elongate, and ultimately leading to creatures like the short-headed land skink, a small, scaly, legless species found in South Africa that doesn't just look like a snake, but also moves a lot like one too.

Like the caecilians and many snakes as well, the majority of legless skinks are fossorial and carnivorous, although fortunately for us, none are known to be venomous.