Artist's reconstructionДиБгд at Russian Wikipedia Hands fixed by FunkMonk., Public domainHerrerasaurus
“Herrera's lizard”An early predator from the dawn of the dinosaurs, named after the goat herder who found it
Overview
Herrerasaurus is likely a genus of saurischian dinosaur from the Late Triassic period. Measuring 6 m (20 ft) long and weighing around 350 kg (770 lb), this genus was one of the earliest dinosaurs from the fossil record. Its name means "Herrera's lizard", after the rancher who discovered the first specimen in 1958 in South America. All known fossils of this carnivore have been discovered in the Ischigualasto Formation of Carnian age in northwestern Argentina. The type species, Herrerasaurus ischigualastensis, was described by Osvaldo Reig in 1963 and is the only species assigned to the genus. Ischisaurus and Frenguellisaurus are synonyms.
Source: Wikipedia
Why it matters
- Lived about 231 million years ago when dinosaurs were still a minor part of the fauna.
- A near-complete skull found in 1988 revealed a sliding jaw joint for gripping struggling prey.
- Its exact place on the family tree, inside or just outside the theropods, is still argued.
Classification & discovery
- Group
- Dinosaur · Early dinosaur · Herrerasauridae
- Parent taxon
- Herrerasauridae
- Diet
- carnivore
- Environment
- terrestrial
- Named
- by Reig in 1963
When it lived
237 – 227.3 million years ago · Triassic
Where it was found
Argentina · Countries with fossils: AR
11 fossil occurrences in the Paleobiology Database · Rock formations: Ischigualasto
Size

Length 4.5 m · Mass 250 kg · Size estimates are editorial, from the literature; silhouettes from PhyloPic.
- Length
- 4.5 m
- Height
- 1.2 m
- Mass
- 250 kg
- First appearance
- 237 MaCarnian
- Last appearance
- 227.3 Ma
- Span of the fossil record
- 9.7 million years
- Fossil occurrences
- 11AR
- Year named
- 1963Reig
Sources
Image: ★Kumiko★, CC BY-SA 2.0 · CC BY-SA 2.0 · image page
Life restoration: ДиБгд at Russian Wikipedia Hands fixed by FunkMonk., Public domain · Public domain · image page
Silhouette: Scott Hartman (PhyloPic) · license
Text: Wikipedia (CC BY-SA 4.0). Taglines, highlights and size estimates are editorial.