Safari Ltd EstemmenosuchusSafari Ltd Estemmenosuchus Estemmenosuchus was a prehistoric creature known as a therapsid. It was not a dinosaur, and actually lived in the Permian period, over 265 million years ago, well before any dinosaurs roamed the earth. Therapsids were early ancestors of what would one day become mammals, and actually had more in common with mammals than reptiles. Safari Ltd Model 100353 Size in cm: 11. 0cm x 6. 0cm x 6. 0cm The Estemmenosuchus is part of the