Stratum.black
Troodon formosus — Troodon formosus
Troodon formosus — Conty, Wikimedia Commons, CC BY 3.0

Dinosaur

Troodon formosus

Troodontid

Troodon formosus was named from a single tooth from the Judith River Formation in 1856, which is why the name is now considered doubtful and the Two Medicine skeletons have been moved to Stenonychosaurus and Latenivenatrix. Troodontid teeth are small, with large hooked denticles on the back edge and a constricted base; they remain a collector favourite from Montana microsites. Label them 'Troodontidae (Troodon formosus sensu lato)'.

PhylumChordata
ClassReptilia
OrderSaurischia
FamilyTroodontidae
GroupDinosaur
Rank (PBDB)genus· Paleobiology Database
AuthorLeidy 1856· Paleobiology Database
Classification (PBDB)Chordata › Reptilia › NO_ORDER_SPECIFIED › Troodontidae· Paleobiology Database
Range (PBDB)83.6–66 Ma· Paleobiology Database
PBDB occurrences103· Paleobiology Database

Photographs

Troodon formosus — Troodon formosus Leidy, 1856
Troodon formosus Leidy, 1856 — Smithsonian Institution (NMNHPALEO), Smithsonian Open Access, CC0

Age

Formations

Elsewhere

Cite this article

Stratum Study. "Troodon formosus" (Taxon). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/taxa/troodon-formosus. Accessed 2026-09-20.

BibTeX · CSL-JSON

@misc{stratum-troodon-formosus,
  title        = {Troodon formosus},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/taxa/troodon-formosus}},
  year         = {2026},
  note         = {Taxon article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, pbdb, wikidata, commons, smithsonian. Accessed 2026-09-20.}
}

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