← Rex's Notes
Therizinosaurus
Giant feathered claws, salad eater.
Said: THER-uh-ZINE-oh-SOR-us
Era: Cretaceous · 70 million years ago
Diet: Herbivore
Habitat: Dry forests of central Asia
Size: as tall as a giraffe with claws longer than your arm.
What it was like
Therizinosaurus had the longest claws of any animal that ever lived — the bone alone was about half a meter, and with the keratin sheath that covers a claw in life, close to a full meter. It used them to pull leafy branches down to its mouth, like garden shears.
What we know now
Despite a theropod ancestry, the body plan converged on a sloth-like browser with a wide gut for fermenting plant material. The claws were almost certainly for foraging, with possible secondary use in display or defense. It is among the largest known feathered animals.
Notes
- Originally classified as a giant sea turtle when first found.
- Feet had four forward-facing toes, unusual for theropods.
- Probably stood upright like a kangaroo to reach high branches.