Fossil Alligator – Alligator prenasalis – This extinct member of the family Alli…

Fossil Alligator – Alligator prenasalis – This extinct member of the family Alligatoridae is the earliest known member of genus Alligator. It is a well known species from many fossils collected in the Oligocene Epoch – 33.9 ± 0.1 to 23.03 ± 0.05 Ma (million years ago) – layer of the Chadron & Brule Formations in South Dakota