Pelycosaur

Informal grouping composed of basal or primitive Late Paleozoic synapsids

Pelycosaur is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term mammal-like reptile had been used, and pelycosaur was considered an order, but this is now thought to be incorrect, and seen as outdated.

This keyword could refer to multiple things. Here are some suggestions: