Nyasasaurus cromptoni

Nyasasaurus (meaning “Lake Nyasa lizard”) is an extinct genus of avemetatarsalian archosaur from the putatively Middle Triassic Manda Formation of Tanzania that may be the earliest known dinosaur. The type species Nyasasaurus parringtoni was first described in 1956 in the doctoral thesis of English paleontologist Alan J. Charig, but it was not formally described until 2013.

Previously, the oldest record of dinosaurs was from Brazil and Argentina and dated back to the mid-late Carnian stage, about 233.23 to 231.4 million years ago. Nyasasaurus comes from a deposit conventionally considered Anisian in age, meaning that it would predate other early dinosaurs by about 12 million years. Some studies cast doubt on this age, suggesting that the deposits may actually be Carnian in age, which would considerably reduce this temporal gap.