Hylonomus

Hylonomus
Temporal range:
Model
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Genus: Hylonomus
Dawson, 1860
Species:
H. lyelli
Binomial name
Hylonomus lyelli
Dawson, 1860
Synonyms
  • Hylonomus latidens
    Dawson, 1882

Hylonomus (/hˈlɒnəməs/; hylo- "forest" + nomos "dweller") 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.