Nyasasaurus (nye-AS-suh-SORE-us) was the earliest-known dinosaur, living about 243 million years ago during the Mid-Triassic in what is now Tanzania. It grew to be about 10 feet (3 meters) long, and was a very early prosauropod.
Nyasasaurus was originally discovered in the 1930's, but wasn't officialy named or described as its own species until December 2012. It was kept in an English museum collecting dust for over 50 years until some scientists started looking through the museum dinosaur-bone storage area and rediscovered this important find. It was unearthed in Tanzania, Africa by Francis Rex Parrington sometime around 1930, and for many years was kept hidden and nearly unkown. It was first described by a paleontologist named Alan J. Charig in 1956, but it was never truly published and wasn't fully described until 2012. It was first found in fossil beds near Lake Nyasa in soil layers that suggested it came from the Mid-Triassic about 243 million years ago.
Nyasasaurus was an early prosauropod that grew to be about 10 feet long, 3 feet (1 meter) tall at the hip, and weigh approximately 135 pounds. Relatively unkown or found is of Nyasasaurus, but we can tell what it may have looked like based on well-known relatives like Plateosaurus. It had a long, extending neck (a feature that would eventually lead to the mega-sauropods that we all know of) with a small head that allowed it to reach higher into trees to get food than before. It could possibly have been both a biped and an quadruped, with sharp claws on each toe for defense. It also had a long tail that strectched over half its body-length that would've been helpful in balancing. Nyasasaurus is currently the oldest-known dinosaur yet found, being 243 million years old, nearly 15 million years older than the previously oldest-known dinosaurs, such as Herrerasaurus, Panphagia, Coelophysis, or Eoraptor. This has shed new light on dinosaur evolution, like how we now know that dinosaurs first evolved from archosaurian reptiles during the Mid-Triassic and not the Late Triassic like we used to believe, and that dinosaurs evolved from relatively small creatures before evolving into the mega-beasts everyone now recognizes. A another middle triassic animal Spondylosoma was unknown for it to be a dinosaur.