ˌ ̷ ̷ ̷ ̷ˈsȯrēə noun plural
Usage: capitalized
Etymology: New Latin, from mes- + -sauria
: an order of primitive aquatic and probably web-footed reptiles from the Permian of So. America and Africa that are distinguished by an elongate head with the nostrils near the eyes and are sometimes included in Pelycosauria as a suborder