DUONYCHUS
a two-fingered therizinosaurid theropod dinosaur from the Late Cretaceous of Mongolia.
Pronunciation: ju-oh-NI-kuss
Meaning: Two claw
Author/s: Kobayashi
et al. (
2025)
Synonyms: None known
First Discovery: Ömnögovi, Mongolia
Discovery Chart Position: #1164
Duonychus tsogtbaatari
(Tsogtbaatar's Two Claw)Etymology
Duonychus is derived from the Greek "duo" (two) and "onyx" (claw), in reference to its didactyl (two fingered) hands.
The
species epithet,
tsogtbaatari, honours Khishigjav Tsogtbaatar, a palaeontologist and former director of the Institute of Paleontology at the Mongolian Academy of Sciences in Ulaanbaatar, Mongolia.
ZooBank registry:
urn:lsid:zoobank.org:act:D0399BA6-4484-458F-A6B4-3CFF59505FE2.
Discovery
The remains of
Duonychus were discovered in the Bayanshiree Formation at the Urlibe Khudak Locality near Khanbogd Town, Ömnögovi Aimag (South Gobi Province), Mongolia, by palaeontologists from the Mongolian Academy of Sciences in 2012.
The
holotype (MPC-D 100/85) is a partial skeleton, including six back vertebrae, some back ribs, a partial left shoulder girdle, both arms and hands, a series of six hip vertebrae with ribs, most of the pelvis, and one tail vertebra.
Preparators
Chagnaa Bayardorj.
Estimations
Timeline:
Era: Mesozoic
Epoch: Late Cretaceous
Stage: Cenomanian-Coniacian
Age range: 95-89 mya
Stats:
Est. max. length: 3 meters
Est. max. hip height: ?
Est. max. weight: 300 Kg
Diet: Herbivore
References
• Shuvalov VF (2000). Page 256–278 in Benton, Shishkin, Kurochkin and Unwin (eds.) "
The Age of Dinosaurs in Russia and Mongolia".
• Kobayashi Y, Chinzorig T, Tsogtbaatar K and Barsbold R (2015)
"A new therizinosaur with functionally didactyl hands from the Bayanshiree Formation (Cenomanian-Turonian), Omnogovi Province, southeastern Mongolia".
Journal of Vertebrate Paleontology. Program and Abstracts.
• Kobayashi Y, Chinzorig T, Fiorillo A, Tsogtbaatar K and Barsbold R (2024)
"Functional morphology and adaptive implications of manual unguals in a therizinosaur with didactyl hand from southern Mongolia".
Society of Vertebrate Paleontology 84th Annual Meeting. Minneapolis, Minnesota, USA. Oct. 30th—Nov. 2nd, 2024. Page 314.
• Kobayashi Y, Zelenitsky DK, Fiorillo AR and Chinzorig T (2025) "Didactyl therizinosaur with a preserved keratinous claw from the Late Cretaceous of Mongolia".
iScience: 112141.
DOI: 10.1016/j.isci.2025.112141.
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To cite this page:
Atkinson, L.
"
DUONYCHUS :: from DinoChecker's dinosaur archive".
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http://www.dinochecker.com/dinosaurs/DUONYCHUS›. Web access: 06th Mar 2026.
