Open Paleo

Adasaurus

Barsbold, 1983 AH-duh-SOR-uhs /ˌɑːdəˈsɔːrəs/

From Mongolian 'ada' meaning 'evil spirit' or 'devil' and Greek 'sauros' meaning 'lizard'; meaning 'evil lizard'

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Adasaurus is a genus of dromaeosaurid dinosaur that lived in Asia during the Late Cretaceous period. The genus is known from two partial specimens found in the Nemegt Formation of Mongolia that were partially described in 1983 by the paleontologist Rinchen Barsbold.

Under dispute

Adasaurus was originally placed in Dromaeosaurinae (Barsbold, 1983), but recent analyses following a firsthand rescoring recover it within Velociraptorinae (Turner and colleagues, 2012; Powers and colleagues, 2020; Napoli and colleagues, 2021), in Napoli and colleagues as the sister taxon of Kuru. It is placed in Velociraptorinae following these analyses.

Diagnosis

  1. Ungual phalanges of reversed digit II highly reduced
  2. Metatarsal II considerably thinned
  3. Predatory claw ungual of reversed digit II reduced to size comparable to supporting digits

Species

Adasaurus mongoliensis Barsbold, 1983

Type species

Named for Mongolia, the country where the holotype was discovered.

Holotype
IGM 100/20 , Paleontological Center, Mongolian Academy of Sciences
Material
Incomplete skull and remains of the postcranial skeleton
Horizon
Nemegt Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Bügiin Tsav, Ömnögovi, Mongolia

References

  1. Barsbold, R. (1977). O evolutsiy chishcheich dinosavrov [On the evolution of carnivorous dinosaurs]. Trudy - Sovmestnaya Sovetsko-Mongol'skaya Paleontologicheskaya Ekspeditsiya 4: 48-56. barsbold1977a
  2. Barsbold, R. (1983). Khishchnye dinozavry mela Mongolii [Carnivorous dinosaurs from the Cretaceous of Mongolia]. Trudy - Sovmestnaya Sovetsko-Mongol'skaya Paleontologicheskaya Ekspeditsiya 19: 1-117. barsbold1983a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026c
  4. Turner, A. H.; Makovicky, P. J.; Norell, M. A. (2012). A Review of Dromaeosaurid Systematics and Paravian Phylogeny. Bulletin of the American Museum of Natural History 371: 1-206. doi:10.1206/748.1

    Recovered Adasaurus firmly within Velociraptorinae after rescoring.

    turner2012a
  5. Napoli, J. G.; Ruebenstahl, A. A.; Bhullar, B. A. S.; Turner, A. H.; Norell, M. A. (2021). A New Dromaeosaurid (Dinosauria: Coelurosauria) from Khulsan, Central Mongolia. American Museum Novitates 2021(3982). American Museum of Natural History (BioOne sponsored). doi:10.1206/3982.1

    New Mongolian dromaeosaurid analysis recovering Adasaurus within Velociraptorinae.

    napoli2021a
  6. Powers, M. J.; Sullivan, C.; Currie, P. J. (2020). Re-examining ratio based premaxillary and maxillary characters in Eudromaeosauria (Dinosauria: Theropoda): Divergent trends in snout morphology between Asian and North American taxa. Palaeogeography, Palaeoclimatology, Palaeoecology 547: 109704. doi:10.1016/j.palaeo.2020.109704

    Analyzed snout ratio characters across eudromaeosaurs, discussing Adasaurus affinities

    powers2020a