Pectinodon (meaning "comb-tooth") is a tooth taxon, since no remains attributable to the genus beyond teeth have been found. Pectinodon seems to be a rare member of the Hell Creek fauna, with their teeth being fairly uncommon (though being so small, I'd guess that few people actively search for them). It was a small Troodontid theropod, with teeth that couldn't handle stresses as well as their Dromaeosaurid and Tyrannosaurid cousins (Torices et al. (2018)). This coupled with their small size suggest that Pectinodon was a small/soft prey specialist, preferring the rodent-sized mammals of the time, lizards, insects, etc. Some researchers have proposed omnivory as a possibility for Troodontids (cf. Holtz et al. (1998)).
Troodontids famously are regarded as among the most intelligent dinosaurs for their large brain size / body size ratio. This notion serves as fodder for speculation that had the dinosaurs not gone extinct, Troodontids (Pectinodon being (one of?) the last) would have continued to grow in intelligence and develop sentience and civilizations.
Troodontid teeth like Pectinodon can be easily identified by their small size, exaggerated, triangular, apically oriented posterior serrations.