These fossil footprints were possibly made by Dimetrodon Natalis millions of years before the first dinosaurs! They were collected in Pueblo, New Mexico and are 270 Million Years Old! Dimetrodon Natalis is the smallest known species of Dinmetrodon!
Dimetrodon is an early member of a group called synapsids, which include mammals and many of their extinct relatives, though it is not an ancestor of any mammal (which appeared millions of years later). As a synapsid, Dimetrodon is more closely related to mammals than to dinosaurs or any living reptile.