The Bactrosaurus is a genus of herbivorous dinosaurs that lived during the Upper Cretaceous period, around 80 million years ago. It was a small to medium-sized dinosaur, with an adult length of nearly 6 meters (20 feet). The Bactosaurus was one of the earliest hadrosaurids and one of this group’s most well-known and studied. The only known species is Bactrosaurus johnsoni, whose fossils have been found in Mongolia, China, and Kazakhstan.

Key Facts

Bactrosaurus pronunciationbak-troh-sore-us
What does Bactrosaurus mean?Club [spined] lizard
Dinosaur typeOrnithopod
On the menuHerbivorous
Length6 meters (20 feet)
Height2.5 m (8 feet 4 inches)
Weight1 ton (about 2200 lbs)
Life expectancyUnknown
Legs used to get aroundQuadruped
Estimated top speedUnknown
When they livedUpper Cretaceous era, 84-71 million years ago
Where they have been found?China

When & Where

The Bactrosaurus was first discovered in 1922 based on a partial skeleton found in the Iren Dabasu Formation in the Gobi Desert of Mongolia. The remains comprised six individual skeletons, ranging from hatchlings to adults. It wasn’t until 1933 that Charles W. Gilmore named and described the species as Bactrosaurus (“club lizard”) due to its characteristic large club-like neural spines. No complete remains have been discovered yet.

Size & Weight

There are grey areas concerning the size and weight of the Bactrosaurus due to its incomplete remains. Scientists, however, describe Bactrosaurus as a small to medium-sized dinosaur, measuring between 6 and 9 meters (20 and 30 feet) in length and with an expected weight of up to 1.5 tonnes. It had a broad body and a short, thick neck. Its head was small and blunt, with eyes facing forward and a beak-like mouth.

Mobility & Diet

The genus Bactrosaurus means “club lizard,” referring to its stocky build and herbivorous diet. It had rows of small, sharp teeth suitable for chewing plant matter. It is thought to have used its beak to crop plants and its teeth to grind them up.

Mobility-wise, the Bactrosaurus had a short tail and walked on all fours. Its legs were relatively long and sturdy, with blunt claws; hence, it was a slow-moving dinosaur.

Interesting Points

  • The Bactrosaurus was a relatively common dinosaur in its habitat.
  • “Bakesosaurus” was once a synonym for this genus, but that name is now considered a junior synonym.
  • The Bactrosaurus was one of the earliest members of the hadrosaurid family, which includes some of the best-known dinosaurs, such as the Edmontosaurus and Parasaurolophus.

Featured image Credit: Levi bernardo, CC BY-SA 3.0, via Wikimedia Commons