Pectinodon is a
dinosaurs from the
mya). It currently contains a single
species, Pectinodon bakkeri (sometimes classified as
Troodon bakkeri), known mainly from teeth, as well as fragments of juvenile skeletons and eggshells.
Kenneth Carpenter named a number of theropod teeth from the late
Lance Formation of
Wyoming as the
type species Pectinodon bakkeri. The generic name is derived from
Latin pecten, "comb", and Greek ὀδών, odon, "tooth", in reference to the comb-like serrations on the rear edge of the teeth. The
specific name honours
Robert Thomas Bakker.
The holotype, UCM 38445, consists of a 6.2 millimetres long tooth. The
paratypes include other teeth and also a front dentary and a lower braincase.
Lev Nesov named a second species: Pectinodon asiamericanus based on specimen CCMGE 49/12176, a tooth from the
Khodzhakul Formation of
Uzbekistan, dating from the
 This is today often considered a
While historically considered synonymous with Troodon or more specifically the species
Philip Currie and colleagues (1990) noted that the P. bakkeri fossils from the
Hell Creek Formation and Lance Formation might belong to different species. In 1991, George Olshevsky assigned the Lance formation fossils to the species Troodon bakkeri.
 In 2011, Zanno and colleagues reviewed the convoluted history of troodontid classification in Late Cretaceous North America. They followed Longrich (2008) in treating Pectinodon bakkeri as a valid genus,
 and noted that it is likely the numerous Late Cretaceous specimens currently assigned to Troodon formosus almost certainly represent numerous new species, but that a more thorough review of the specimens is required.
In 2013 Currie and
Derek Larson concluded that Pectinodon bakkeri was valid and its teeth could be found both in the Lance Formation and the coeval Hell Creek Formation. Some teeth from the older
Dinosaur Park Formation could not be statistically differentiated from them, likely due to an insufficiently large sample, and were referred to a cf. Pectinodon.