Fun Riojasaurus Facts For Kids

The Riojasaurus was a Sauropodomorph that lived during the late Triassic period, in the Norian age. It was alive close to 225-219 million years ago.

The Riojasaurus fossil was found in South America, in northwest Argentina, in the La Rioja province. The Riojasaurus name means 'the lizard that roamed La Rioja'.

The exact site it was discovered was the Los Colorados formation, in the Ischigualasto-Villa Unión Basin. It was the only Riojasaurid to have been found in the continent of South America. The Riojasaurus was a plant-eating herbivore.

It had a small head, large eyes, a slightly built skull, a snout that was blunt, large hands and slender feet with five digits, and finally a long tail. Its elephant-like legs had claws and its hands and feet each had five digits.

Since these Riojasaurus dinosaurs could not stand on their legs, they could not reach higher for eating tall vegetation. They are also thought to have consumed pebbles to help them digest their food.

For more relatable content, check out these Ostafrikasaurus facts and Heterodontosaurus facts for kids.

Riojasaurus Interesting Facts

How do you pronounce 'Riojasaurus'?

Riojasaurus is pronounced as 'Re-o-jah-sore-us'.

What type of dinosaur was a Riojasaurus?

The Riojasaurus (Riojasaurus incertus) was a Sauropodomorph dinosaur.

In which geological period did the Riojasaurus roam the Earth?

Riojasaurus dinosaurs lived on Earth during the Norian stage of the late Triassic period, about 225-219 million years ago.

When did the Riojasaurus become extinct?

The Riojasaurus (Riojasaurus incertus) went extinct 219 million years ago.

Where did a Riojasaurus live?

The Riojasaurus skeleton was discovered in South America, specifically in northwest Argentina. Within Argentina, it was uncovered in the La Rioja province, in the Los Colorados Formation and the Ischigualasto-Villa Unión Basin. The Riojasaurus can be said to have walked these lands, which today belong to the continent of South America.

What was a Riojasaurus's habitat?

The Riojasaurus (Riojasaurus incertus) lived in terrestrial and forest habitats with plenty of plant material and vegetation to supplement its herbivorous diet.

Who did a Riojasaurus live with?

It is unclear whether the Riojasaurus was a solitary or social dinosaur. Being a herbivore, it is more likely to have lived in groups or herds.

How long did a Riojasaurus live?

The Riojasaurus would have lived at the higher end of the 30-100 year age range.

How did they reproduce?

The Riojasaurus reproduced by mating and laying eggs from which infant 'nestling' dinosaurs would hatch. There has been no evidence of parental care in Riojasaurus dinosaurs.

Riojasaurus Fun Facts

What did a Riojasaurus look like?

The Riojasaurus was a massive quadrupedal (walked on four legs) herbivore. This 'La Rioja lizard' was about 29.5-36.1 ft (9-11 m) long and was heavily built. It had a long neck; a long tail; a small head; a long, heavy body; and thick, elephant-like legs with claws.

Its back legs were only slightly larger than its front legs. Its limb bones were solid and thick, but its backbone was hollow. It had spoon-shaped, serrated teeth.

The Riojasaurus size was massive and it walked on four legs, i.e. it was quadrupedal.

It is believed to have been 32.8 ft (10 m) in length on average. Previously its length was thought to be lower, close to 21.7 ft (6.6 m).

The Riojasaurus had bulky legs, a heavy body, a long tail, and a long neck. Bones in the legs of the Riojasaurus were dense when considering other early Sauropodomorphs.

Vertebrae of the Riojasaurus were lightened by cavities that were hollow. Most early Sauropodomorphs had three sacral vertebrae, whereas the Riojasaurus had four.

The Riojasaurus moved around very slowly and it was not able to stand up on its hind legs or back legs. Hind limbs and forelimbs of the Riojasaurus were almost of equal length which suggests that the gait was obligatorily quadrupedal.

In the year 2016, Scott Harman discovered the anatomy of the hand, that the back was almost straight and the shoulder girdle was mostly immobile, which is slightly suggestive that some Riojasaurus dinosaurs may have been bipeds too. The backbone of these dinosaurs was hollow, and limb bones were thick and solid.

There was no skull found when the first Riojasaurus skeleton was found. However, a preserved attribute of the Riojasaurus skull was found later, which were teeth.

Riojasaurus teeth were serrated and spoon or leaf-shaped. There were five teeth in the upper jaw, as well another 24 teeth behind them, under the eyes, in a row.

There have been comparisons between scleral rings of modern birds and those of Riojasaurus dinosaurs which suggest that they were active for short intervals all throughout the day, and led a cathemeral lifestyle. Scleral rings are rings around the eyes in many vertebrate animals, except crocodilians and mammals.

Overall, the Riojasaurus can be summarized as a dinosaur with a small head, big eyes, a skull that was lightly built, a blunt snout, large forelimbs, hands with five fingers, slender feet with five toes, larger hind limbs or back legs, and a long tail. Its body was bulky and its legs were elephant-like and had claws.

How many bones did a Riojasaurus have?

The exact number of bones that the Riojasaurus had is not known yet.

How did they communicate?

The way that these Riojasaurus dinosaurs communicated is speculative. There must have been mating and territorial displays along with sound cues like grunts, bellows, and hoots.

How big was a Riojasaurus?

The Riojasaurus was 21.7-36.1 ft (6.6-11 m) long which makes the 'La Rioja lizard' two times bigger than the Akainacephalus.

How fast could a Riojasaurus move?

Exact speeds of these Riojasaurus dinosaurs are unknown but by observing their ankle and leg structure, it has been surmised that these dinosaurs weren't fast movers and that they couldn't stand on their hind legs.

How much did a Riojasaurus weigh?

Considering its size, the Riojasaurus easily weighed 1,763.7-6,613.9 lb (800-3,000 kg).

What were the male and female names of the species?

The are no specific male and female names for the Riojasaurus genus and species of dinosaurs. But as with other dinosaur names, suffixes 'saura' and 'saurus' can be applied to male and female names respectively.

What would you call a baby Riojasaurus?

A baby Riojasaurus would be called a nestling or a hatchling.

What did they eat?

Riojasaurus dinosaurs were plant-eating herbivores that ate plant materials and vegetation.

These large dinosaurs were unable to stand on their hind legs, so they didn't reach higher vegetation. Also, they might have consumed pebbles to aid food digestion.

How aggressive were they?

It is difficult to say if these Riojasaurus dinosaurs were aggressive. They may have fought against one another for mating and territorial rights, but they were plant-eating herbivores so they definitely didn't bother other animal species.

Did you know?

One of the interesting Riojasaurus facts was that it had low intelligence when compared to other dinosaurs. This was determined by comparing its small brain size to its massive body.

Along with the Dinosauria clade, the Riojasaurus belongs to the clade Saurischia, the order of large dinosaurs that are lizard-hipped. It was also a Sauropodomorph and possibly a Melanorosaurid since Melanorosaurids were also big, quadrupedal, and thick-limbed. The Riojasaurus dinosaur was the only Riojasaurid to have inhabited South America.

Riojasaurus translates to 'the lizard that lived in La Rioja'.

Many scientists think that the Riojasaurus was closely related to the Melanorosaurus, known from the Triassic-early Jurassic period. However, studies at Bristol University, England, suggest that it is unique in some key ways, such as long bones in its neck. It is certainly quite different from other Sauropodomorphs found in the Los Colorados formation of Argentina.

Did the Riojasaurus live alone or in herds?

It is not clear whether the Riojasaurus lived alone or in groups.

Did the Riojasaurus sit on its nest?

It is not known whether the Riojasaurus sat on its nest.

Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! Learn more about some other dinosaurs from our Chungkingosaurus fun facts for kids and Sauropelta interesting facts pages.

You can even occupy yourself at home by coloring in one of our free printable Riojasaurus coloring pages.

Second image by Nobu Tamura.