Hylonomus

Extinct genus of reptiles

Hylonomus is an extinct genus of reptile that lived 318 million years ago during the Bashkirian stage of the Late Carboniferous. It is the earliest known crown group amniote and the oldest known unquestionable reptile, with the only known species being Hylonomus lyelli. Despite being amongst the oldest known reptiles, it is not the most primitive member of the group, being a eureptile more derived than either parareptiles or captorhinids.

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