Dino card No. 0798 of 2,027

Herrerasaurus

Say it: heh-RAIR-uh-SORE-us

Name means: “Herrerasaurus means 'Herrera's lizard', named after a rancher named Herrera.”4

Ate: MeatFirst dinosaursLate Triassic

Herrerasaurus was one of the very first dinosaurs. It was a fast, two-legged hunter with sharp claws and teeth. It lived in Argentina about 230 million years ago.1 4

Lived

237 to 227 million years ago4

Late Triassic

Fossils found in

Fossils were found in the Ischigualasto Formation in Argentina, in the provinces of San Juan and La Rioja.4 2

Food

Meat1

Length

3 to 6 m4

Scientists think it was about 3 to 6 metres long, but the exact size is uncertain.

Weight

30 kg to 300 kg4

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How long was it?

How heavy was it?

as heavy as 10 big dogs

as long as 6 dogs nose to tailas long as 33 bananas end to endas heavy as 60 watermelons

How big was Herrerasaurus compared to YOU?

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cool stuff

Fun facts

Herrerasaurus had a short forelimb that was specialized for grasping and raking, making it a skilled predator.1

It lived during the Carnian age, about 237 to 227 million years ago, which is very early in dinosaur history.4

Some scientists used to think Herrerasaurus was not a true dinosaur, but now most agree it was an early theropod.2

Herrerasaurus is the type genus of the family Herrerasauridae, a group of early meat-eating dinosaurs.2

The first fossils were found in 1963, but a complete skull and skeleton were not unearthed until 1992.1 4

Herrerasaurus was an agile, bipedal predator, meaning it walked on two legs and was quick on its feet.1

AI-made picture of Herrerasaurus — An AI-made picture of how Herrerasaurus might have looked, made by a computer from what scientists know. It is a guess: the real animal may have looked different, and nobody knows its true colours.

you asked

Most asked questions about Herrerasaurus

?How big was Herrerasaurus?

Herrerasaurus was about 6 metres (20 feet) long and weighed around 350 kilograms (770 pounds). Smaller specimens were about 4.5 metres (15 feet) long and weighed about 200 kilograms (440 pounds).3

?What did Herrerasaurus eat?

Herrerasaurus was a carnivore, meaning it ate meat. It had large serrated teeth for biting and eating flesh, and sharp claws for grasping prey.3

?When did Herrerasaurus live?

Herrerasaurus lived during the Late Triassic period, about 231 to 228 million years ago, during the Carnian age. That's very early in dinosaur history.3

?Where was Herrerasaurus found?

Herrerasaurus fossils have been found in the Ischigualasto Formation in northwestern Argentina, South America. The first specimen was discovered in 1958 by a rancher named Victorino Herrera.3

?Was Herrerasaurus a dinosaur?

Yes, Herrerasaurus is considered an early dinosaur. For many years scientists debated whether it was a true dinosaur, but now most agree it was an early saurischian dinosaur, possibly a primitive theropod.3

?How fast could Herrerasaurus run?

Herrerasaurus was likely a swift runner. It had strong hind limbs with short thighs and long feet, and a stiff tail for balance, all adaptations for speed.3

?Did Herrerasaurus have feathers?

The sources do not mention feathers on Herrerasaurus. It lived very early in dinosaur history, and no feather fossils have been found with it.3

?Why is Herrerasaurus important?

Herrerasaurus is important because it is one of the earliest known dinosaurs. Its fossils help scientists understand the early evolution of dinosaurs and what the common ancestor of all dinosaurs might have looked like.3 1

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Myth buster

Myth: Some people think Herrerasaurus was a dinosaur like T. rex, but it was much older and more primitive.

Truth: Herrerasaurus was an early dinosaur, but it lived about 230 million years ago, long before T. rex. It had a shorter forelimb and a more primitive body.1

For dino experts

Scientific name: Herrerasaurus
Named by: Reig 19634
Group: First dinosaurs
Family / clade: Herrerasauridae4
Classification: Herrerasauridae4
Age of the rocks: 237 to 227 million years (Carnian)4
Rock formations: Ischigualasto4
Countries: Argentina4
Fossil records: 11 in the Paleobiology Database4
Also known as: Frenguellisaurus, Ischisaurus (older names now counted as the same animal)4
Discovery: Herrerasaurus was named by Osvaldo Reig in 1963, based on fossils found in Argentina. Later, a complete skull and skeleton were discovered in the Ischigualasto Formation, helping scientists understand its anatomy.4 1
Still debated: Scientists still debate whether Herrerasaurus was a true theropod or a more primitive dinosaur, because it has features of both.2

Where the facts come from

The Complete Skull and Skeleton of an Early Dinosaur (science.org)
PBDB Taxon (paleobiodb.org)
Herrerasaurus (en.wikipedia.org)
Herrerasaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.

Every fact on this page has a number that points to its source. If we got something wrong, sorry, we are dino fans, not a science journal. Tell us at [email protected] and we will fix it.

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