Pisanosaurus
Order: Ornithischia
Pisanosaurus is considered to be the earliest ornithischiandinosaur. It lived during the Late Triassic period, millions of years before any other bird-hipped dinosaur appeared. Its presence inthe same formation in Argentina as the primitive theropods Herrerasaurus and Eoraptor imply that, if dinosaurs share a common ancestor, the common ancestor occurred earlier than these specimens, which are the earliest known dinosaurs. Small, with long, slender feet, Pisanosaurus probably was a good runner. Scientists think that it belongs to the heterodontosaur family. If it is a heterodontosaurid, a group also found in Africa, its existence is further evidence that these continents were still joined together during the Late Triassic Period.
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Reference background: Natural History Museum, London — Dinosaurs; Smithsonian National Museum of Natural History — Dinosaurs; American Museum of Natural History — Dinosaurs & Fossils. Figures are typical published ranges; taxonomy follows the source era and modern consensus is noted where it differs. See our sources & fact-check policy.
Frequently asked questions
What does Pisanosaurus mean?
The name Pisanosaurus means “Pisano's Lizard”. It is pronounced pye-SAN-uh-SAWR-us.
When did Pisanosaurus live?
Pisanosaurus lived during the Late Triassic.
Was Pisanosaurus a carnivore or a herbivore?
Pisanosaurus was a herbivore.
How big was Pisanosaurus?
Pisanosaurus was about 36 inches (0.9 meters) long, around 24 inches (0.6 meters) tall, weighing up to 8 pounds (3.6 kg).
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