The invincible dinosaur


  • Name: Pinacosaurus
  • Diet: Herbivore
  • Weight: 2 tons
  • Period: Cretaceous
  • Found In: China

Pinacosaurus seems to have been one of the most abundant Asian ankylosaurs given the large number of fossil remains found for this genus. This large quantity is combined with the high level of preservation in many of the specimens. It means that the validity of the genus is indisputable.

What does the name Pinacosaurus mean?

Pinacosaurus means “board lizard“, deriving its name from the heavy armor of its body and the characteristic tail of the ankylosaurs, as these had a purpose above all others: to make them too tough for predators to kill.

History of the Pinacosaurus discovery

The first Pinacosaurus fossils were found in many known places, such as: China, Ningxia Hui Autonomous Region, Mongolia- Bayan Mandahu Formation, Djadokhta Formation.

More than 35 incomplete fossils have been found, many in large bones, indicating that Pinacosaurus may have roamed in herds, mainly in Mongolia, Asia and was named by Charles Gilmore in 1933.

Exciting Pinacosaurus findings

An exciting finding associated with Pinacosaurus is the discovery of several juveniles that died while huddled together. It is believed that these individuals were suffocated when buried in a sandstorm, but the circumstances of death are not so much

But the facts show that, at the very least, young people would live in groups, presumably because of the greater protection they get from predators.

It is not yet known for sure whether ankylosaurs like Pinacosaurus lived in groups as adults, but animals that eat vegetables often cluster together and travel together so that it is more difficult for predators to catch them.

Pinacosaurus Classification

At the time of its initial description by Gilmore, Pinacosaurus was actually considered a nodosaur, a member of a group of armored dinosaurs that are considered to be both related and ancestral to ankylosaurs, although they continued to live alongside ankylosaurs after they appeared.

For clarity, Pinacosaurus is now considered to be Ankylosaurine Ankylosaur, meaning that it is related to more advanced Ankylosaur forms. Of these genera Pinacosaurus has been considered to be more closely related to Minotaurasaurus (Thompson et al 2011)

When and where did the Pinacosaurus live?

Pinacosaurus lived right in the late Cretaceous, about 81 to 85 million years ago. The Cretaceous period was the height of the dinosaurs. Huge carnivores like Tyrannosaurus Rex and Giganotosaurus appeared, as did Triceratops and many, many others.


There was a great diversity in the dinosaur species. Mammals were flourishing and flowering plants were developing to radically change the landscape.

Pinacosaurus origin

The disintegration of the supercontinent Pangaea into separate continents was underway. The separation of Laurasia and Gondwana was complete. In the first half of the Cretaceous, temperatures were warm, seasonality was low, and global sea levels were high (no polar ice!) At the end of the Cretaceous, there were severe climatic changes, decreased sea levels and high volcanic activity, and it was right there where the Pinacosaurus developed.

The Cretaceous period ended 65 million years ago with the extinction of the dinosaurs and many other prehistoric life forms. This mass extinction was the second largest in the history of the Earth.

Pinacosaurus description

  • Pinacosaurus was its atypical ankylosaur, wide and stocky body, armored shields on the back, club tail, all mounted on four short, stubby legs.
  • The egg-shaped holes in the skull that appear where the nostrils are normally located are some of the holes found in two pairs, but in one juvenile specimen five pairs were listed.
  • Of these pairs there is one variation, and it is possible that the juveniles had more than the adults, or that they may represent another new species of Pinacosaurus.

Pinacosaurus nostrils

Why the nostrils were there is also a mystery, although ankylosaurs are characterized by more complex nasal passages than other types of dinosaurs, and these adaptations reduce moisture loss through respiration in arid environments.

This does not sufficiently explain why Pinacosaurus had additional holes when other genera do not. However, it is possible that the holes were a sexually selected characteristic that allowed Pinacosaurus to identify itself among the other genera of upper Cretaceous ankylosaurs, such as Talarurus.

Curiosities about Pinacosaurus

Pinacosaurus was a medium size, armored, beaked, quadruped with a slim constitution. It had a rump, bony barbs along its back and tail, but no armor on its muzzle.

Pinacosaurus had lit nasal fins, four large toes covered by the hoof on its front legs and five toes on each of its hind legs, being particular enough for the group in which its classification has been placed.