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Paronychodon

Paronychodon
Temporal range: Late Cretaceous, 75–66 Ma
Paronychodon.png
Two referred teeth
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Family: Troodontidae
Genus: Paronychodon
Cope, 1876
Type species
Paronychodon lacustris
Cope, 1876
Species
  • P. lacustris Cope, 1876
  • P. caperatus (Marsh, 1890 [originally Tripriodon])

Paronychodon (meaning "beside claw tooth") was a theropod dinosaur genus. It is a tooth taxon, often considered dubious because of the fragmentary nature of the fossils, which include "buckets" of teeth but no other remains.

The type species, named by Edward Drinker Cope in 1876, is Paronychodon lacustris, from the Judith River Formation of Montana, dating to 75 million years ago, during the Campanian stage. The holotype is specimen AMNH 3018. It is a tooth about one centimetre long, elongated, recurved, lacking serrations, possessing low vertical ridges and with a D-shaped cross-section, the inner side being flattened. Cope at first thought the tooth belonged to a plesiosaur, but the same year realised it represented a carnivorous dinosaur.

A second species, Paronychodon caperatus, is known from the Hell Creek Formation of North Dakota, Montana, and South Dakota and Lance Formation of Wyoming (latest Maastrichtian stage, 66 million years ago) and was originally referred to the mammal genus Tripriodon by Othniel Charles Marsh in 1889, but placed in Paronychodon by George Olshevsky in 1991. It is based on holotype YPM 10624, a tooth close in form to the holotype of P. lacustris but somewhat larger. In 1995 Olshevsky renamed Laelaps explanatus Cope 1876 into a Paronychodon explanatus; today the taxon is seen as based on Saurornitholestes teeth.


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Wikipedia

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