Hylonomus

Hylonomus (/haɪˈlɒnəməs/; hylo- "forest" + nomos "dweller")[1] is a genus of reptile that lived 312 million years agoduring the Late Carboniferous period.[2] It is the earliest unquestionable reptile (Westlothiana is older, but in fact it may have been an amphibian, and Casineria is rather fragmentary). The only species is the type species Hylonomous lyelli.