Dino card No. 1184 of 2,027

Mierasaurus

Say it: mee-ER-ah-SORE-us

Name means: “Bernardo de Miera's lizard, after the Spanish cartographer Bernardo de Miera y Pacheco”1 2

Ate: PlantsLong-necksEarly Cretaceous

Mierasaurus was a giant long necked plant eater that lived in what is now Utah, USA. It was one of the last survivors of an older group of sauropods, the turiasaurs, that were once only known from Europe. Its fossils are some of the most complete sauropod remains ever found in North America.1 2

Lived

139 to 133 million years ago5

Early Cretaceous

Fossils found in

Doelling's Bowl, Grand County, east central Utah, USA5 1 2

Food

Plants5 1

Length

11.5 m3

largest known specimen

Weight

4.8 tonnes3

largest known specimen

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 3 cars

as long as 2.5 cars parked in a rowas long as 64 bananas end to endabout as heavy as an elephantas heavy as 960 watermelons

How big was Mierasaurus compared to YOU?

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cool stuff

Fun facts

Mierasaurus is named after Bernardo de Miera y Pacheco, the first European scientist to explore Utah in 1776.1 2

Its fossils were dug up from a huge bone bed covering about 5,000 square meters, like almost one and a half football fields.2

Mierasaurus is a turiasaur, a group of sauropods that scientists thought lived only in Europe until this dinosaur was found in North America.1

The type specimen is a subadult, because some bones like the vertebrae were not fully fused together.1

The Doelling's Bowl site has also produced bones of an iguanodont dinosaur and a spiky armored ankylosaur.1

Mierasaurus lived during the Early Cretaceous, about 136 to 132 million years ago.2 5

AI-made picture of Mierasaurus — An AI-made picture of how Mierasaurus 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 Mierasaurus

?How big was Mierasaurus?

Scientists do not know its exact size yet, but it was a large sauropod. The only known skeleton is from a subadult, so it was still growing when it died.2 4

?What did Mierasaurus eat?

Mierasaurus was a plant eater. It had heart-shaped teeth that helped it strip leaves from plants.2

?Where was Mierasaurus found?

Its fossils were found in east-central Utah, USA, at a site called Doelling's Bowl in the Cedar Mountain Formation.2 4

?Is Mierasaurus a dinosaur?

Yes, Mierasaurus is a dinosaur. It is a type of sauropod, which is a long-necked, plant-eating dinosaur.2

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For dino experts

Scientific name: Mierasaurus
Named by: Royo-Torres et al. 20175
Group: Long-necks
Family / clade: Turiasauria5
Classification: Sauropodomorpha > Sauropoda5
Age of the rocks: 139 to 133 million years (Berriasian / Valanginian)5
Rock formations: Cedar Mountain5
Countries: USA5
Fossil records: 1 in the Paleobiology Database5
Discovery: Mierasaurus was named and described in 2017 by Rafael Royo-Torres and colleagues. They studied a mostly complete skeleton dug up at Doelling's Bowl in eastern Utah, USA, during excavations by the Utah Geological Survey starting in 2005.1 2
Still debated: Scientists are not sure exactly how big Mierasaurus grew, because the only known skeleton is from a subadult that had not finished growing.1

Where the facts come from

preview-www.nature.com (preview-www.nature.com)
Mierasaurus (en.wikipedia.org)
Mierasaurus bobyoungi | Dinosaur Database by DinoAnimals.com (dinoanimals.com)
Descendants of the Jurassic turiasaurs from Iberia found refuge in the Early Cretaceous of western USA | Scientific Reports (nature.com)
Mierasaurus 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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