# Therizinosaurus cheloniformis

> A giant therizinosaur from the Late Cretaceous Nemegt Formation of Mongolia, known mainly from its arms and huge hand claws. A theropod that most likely ate plants.

- Classification: Dinosauria (clade) > Saurischia (clade) > Theropoda (clade) > Coelurosauria (clade) > Maniraptora (clade) > Therizinosauria (clade) > Therizinosauridae (family) > Therizinosaurus (genus) > Therizinosaurus cheloniformis (species)
- Length: 9–10 m
- Hip height: 2.8–3.5 m
- Mass: 5 t
- Age: 72.1–66 million years ago (Late Cretaceous)
- Fossils found in: Nemegt Formation (Ömnögovi Province); Mongolia
- Diet: herbivore
- Described: Evgeny Maleev, 1954
- In films: Jurassic World Dominion (2022)

Canonical page: https://dinodex.club/dinosaurs/therizinosaurus-cheloniformis
Last updated: 2026-09-27

## Overview

Therizinosaurus cheloniformis lived in what is now the Gobi Desert of Mongolia in the Late Cretaceous. Evgeny Maleev named it in 1954 from enormous flat claws found by a Soviet-Mongolian expedition in the Nemegt Formation, and he took them for the remains of a giant turtle-like reptile.

Later finds of arms and hind limbs showed it was a theropod, part of the strange group Therizinosauria (Zanno 2010). Its relatives had small heads, long necks, broad bellies and four-toed feet. Therizinosaurus itself is known only from limbs and a few other bones, so its full body is reconstructed from those relatives.

Its hand claws are among the longest of any known animal. Despite belonging to the meat-eating theropods, therizinosaurs show leaf-shaped teeth, beaks and wide guts, and Zanno and Makovicky (2011) treat the group as herbivorous. The claws were probably used for pulling down branches, display or defence rather than hunting.

## Name meaning

From Greek therizo ("to reap") and sauros ("lizard"): "reaping lizard", for the scythe-like claws; cheloniformis means "turtle-shaped", from Maleev's first interpretation (Maleev 1954).

## Sources

1. Cohen, K. M., Harper, D. A. T., Gibbard, P. L. & Car, N. (2023). International Chronostratigraphic Chart (v2023/09). International Commission on Stratigraphy. https://stratigraphy.org/ICSchart/ChronostratChart2023-09.pdf
2. Maleev, E. A. (1954). Novyy cherepakhoobraznyy yashcher v Mongolii [New turtle-like reptile in Mongolia]. Priroda 1954(3): 106-108.
3. Paul, G. S. (2010). The Princeton Field Guide to Dinosaurs. Princeton University Press.
4. Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd edition). Princeton University Press.
5. Zanno, L. E. (2010). A taxonomic and phylogenetic re-evaluation of Therizinosauria (Dinosauria: Maniraptora). Journal of Systematic Palaeontology 8(4): 503-543. https://doi.org/10.1080/14772011003644595
6. Zanno, L. E. & Makovicky, P. J. (2011). Herbivorous ecomorphology and specialization patterns in theropod dinosaur evolution. Proceedings of the National Academy of Sciences 108(1): 232-237. https://doi.org/10.1073/pnas.1011924108

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Cite as: "Therizinosaurus cheloniformis". DinoDex. https://dinodex.club/dinosaurs/therizinosaurus-cheloniformis (updated 2026-09-27).