card
004

Alxasaurus elesitaiensis

OLogy Series
extinct animal
card
004

Alxasaurus elesitaiensis

OLogy Series
extinct animal

Dug up in the Alxa Desert in China, Alxasaurus is the oldest and most complete therizinosaur (theh-rih-ZEEN-uh-sawr) ever found. It had a small skull, relatively long neck, long arms, a short tail, and weighed about 750 pounds. Therizinosaurs are known for their big claws.

Those Pesky Therizinosaurs!
Big-clawed dinosaurs called therizinosaurs puzzle paleontologists. These Cretaceous dinosaurs have left few fossils behind. Those fossils that have been found are incomplete and random -- a lower jaw from one specimen, a hip from another... The first Therizinosaurus fossils found had arm bones with gigantic claws, so scientists thought it was a turtle-like creature not even related to dinosaurs. Since Alxasaurus is the most complete therizinosaur found so far. This species helps answer questions about the anatomy and evolution of all therizinosaurs.

In terms of its diet, Alxasaurus was:

a plant-eater or "herbivore"

a meat-eater or "carnivore"

no one knows

Are you right?

Correct!

It has some plant-eater features, like a beak and cheek teeth, but is closely related to meat-eaters. Alxasaurus is a mysterious dinosaur.

Therizinosaurs had feathers.

Fact
or
Fiction
?

Fact

Beipiaosaurus from the Early Cretaceous period of China is an early therizinosaur, and also the largest dinosaur found with traces of feathers.

Therizinosaurus had 8-foot-long arms with 27-inch claw bones.

Fact
or
Fiction
?

Fact

In life, its actual claws were even bigger, because the nails aren't usually fossilized.

Alxasaurus elesitaiensis "Alxa Desert lizard"
(AHL-shah-SAW-rus eh-leh-SIT-ay-en-sis)
Locality found: Alxa Desert, Inner Mongolia, China
Age: Early Cretaceous, 105 MYA
Size: 13 feet long, 750 pounds
Characteristics: Like many herbivorous dinosaurs, Alxasaurus had a toothless beak and cheek teeth. Its diet, however, is not known.

Image credits: Rick Spears.