Therizinosaurus cheloniformis thair-ih-ZEEN-oh-SOR-us
"Scythe lizard"
You 1.8 m (5.9 ft) tall
Therizinosaurus 10 m (33 ft) long
6 people holding hands
- Length
- 10 m (33 ft) — About 10 m long, ~5 tonnes — with claws up to 1 m long.
- Period
- Late Cretaceous (72–68 Mya)
- Place
- Asia · Mongolia
- Food
- Herbivore — Leaves and high branches — used the long arms and claws like a giant tree-leaf rake.
Therizinosaurus was a meat-eater that gave up meat. Its ancestors were sharp-toothed coelurosaurs, but Therizinosaurus evolved a wide gut, a small head, and meter-long claws that it used to pull branches down to its mouth. It looked like nothing else in the dinosaur world — part giant sloth, part ground bird, part oversized turkey with kitchen knives.
What we know
- Claws up to 1 m long — the largest of any known animal.
- Wide-bellied build with a small head and a long neck, like other plant-eating theropods.
- Coelurosaur — closely related to oviraptors and tyrannosaurs.
- Lived alongside Tarbosaurus in the Nemegt Formation of Mongolia.
What we guess
- What the giant claws were for — leaves, defense, mating display, or all three.
- Feathered body covering — almost certain given its relatives, but no preserved feathers yet.
- Whether it could rear up on two legs to reach high branches like a giant ground sloth.