Open Paleo

Paronychodon

Cope, 1876 PAH-ro-NIK-o-don Nomen dubium

From Greek 'para' meaning 'beside', 'onyx' meaning 'claw', and 'odon' meaning 'tooth'; translates as 'beside claw tooth', referring to the claw-like nature of the tooth.

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Paronychodon is an extinct theropod dinosaur genus. It is a tooth taxon, often considered dubious because of the fragmentary nature of the fossils, which include "buckets" of teeth from many disparate times and places but no other remains, and should be considered a form taxon.

Under dispute

The teeth assigned to Paronychodon lacustris cannot be placed below Paraves. Currie and colleagues (1990) referred most of them to known theropods such as Troodon and Saurornitholestes, as probable growth abnormalities, and Sues and Averianov (2013) regard them as possible developmental stages of various paravian theropods, whose affinities "remain uncertain".

Species

Paronychodon lacustris Cope, 1876 Nomen dubium

Type species

From Latin 'lacustris' meaning 'belonging to a lake' or 'lake-dwelling', referencing the marshy, lacustrine environment inferred for the beds that yielded the holotype.

Holotype
AMNH 3018 , American Museum of Natural History
Material
Teeth with semicircular crown section, longitudinal plicae, curved edges
Horizon
Judith River Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Montana, United States The erecting paper is titled for "the Fort Union Beds of Montana", but uses that name for the Fort Union bad lands of the Judith River, and later workers likewise place its fauna in the Judithian beds of Montana. No locality within Montana is published, so none is recorded.

Synonyms of the genus

Name Type Reason
Euronychodon junior subjective Sues and Averianov (2013) found the type teeth of Euronychodon portucalensis Antunes and Sigogneau-Russell, 1991 indistinguishable from the Paronychodon morphotype.

References

  1. Cope, E. D. (1876). Descriptions of some vertebrate remains from the Fort Union Beds of Montana. Proceedings of the Academy of Natural Sciences of Philadelphia 28: 248-261.

    Erects the species on teeth from "the Fort Union Beds of Montana", which the text equates with the bad lands of the Judith River. Gives no locality beyond that.

    cope1876a
  2. Currie, P. J.; Evans, D. C. (2019). Cranial Anatomy of New Specimens of Saurornitholestes langstoni (Dinosauria, Theropoda, Dromaeosauridae) from the Dinosaur Park Formation (Campanian) of Alberta. The Anatomical Record 303(4): 691-715. Wiley. doi:10.1002/ar.24241

    Places the tooth taxa named in this paper and its companion among species from the Judithian-aged beds of Montana, the source of the formation.

    currie2019a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Lists the genus as a tooth taxon, most likely from a eumaniraptoran.

    jones2026c
  4. Currie, P. J.; Rigby, J. K.; Sloan, R. E. (1990). Theropod teeth from the Judith River Formation of southern Alberta, Canada. Dinosaur Systematics: Perspectives and Approaches (Carpenter, K.; Currie, P. J., eds.) 107-126. Cambridge University Press, Cambridge. doi:10.1017/cbo9780511608377.011

    Referred most Paronychodon-type teeth to known genera as growth abnormalities and restricted the name to unserrated teeth.

    currie1990a
  5. Sues, H. D.; Averianov, A. (2013). Enigmatic teeth of small theropod dinosaurs from the Upper Cretaceous (Cenomanian–Turonian) of Uzbekistan. Canadian Journal of Earth Sciences 50(3): 306-314. doi:10.1139/e2012-033

    Treated Paronychodon as an organ taxon, not a diagnosable species; possibly developmental stages of various paravians.

    sues2013a
  6. Makovicky, P. J.; Norell, M. A. (2004). Troodontidae. The Dinosauria, Second Edition (Weishampel, D. B.; Dodson, P.; Osmólska, H., eds.) 184-195. University of California Press, Berkeley.

    Listed Paronychodon lacustris as a nomen dubium in Troodontidae.

    makovicky2004b
  7. Antunes, M. T.; Sigogneau-Russell, D. (1991). Nouvelles données sur les dinosaures du Crétacé supérieur du Portugal [New Data on the Dinosaurs of the Upper Cretaceous of Portugal]. Comptes Rendus de l'Académie des Sciences, Paris, Série II 313: 113-119.

    Named Euronychodon portucalensis for unserrated teeth from Taveiro, Portugal, as a dromaeosaur related to Paronychodon.

    antunes1991a
  8. Csiki-Sava, Z.; Buffetaut, E.; Ősi, A.; Pereda-Suberbiola, X.; Brusatte, S. L. (2015). Island life in the Cretaceous — faunal composition, biogeography, evolution, and extinction of land-living vertebrates on the Late Cretaceous European archipelago. ZooKeys 469: 1-161. doi:10.3897/zookeys.469.8439

    Reports Euronychodon as a subjective junior synonym of Paronychodon.

    csiki-sava2015a