Troodon (/ˈtroʊ.ədɒn/ TROH-ə-don; Troödon in older sources) is a genus of relatively small, bird-like dinosaurs known definitively from the Campanian age of the Cretaceous period (about 77 mya), though possible additional species are known from later in the Campanian and also from the early (and probably late) Maastrichtian age. It includes at least one species, Troodon formosus, though many fossils, possibly representing several species have been classified in this genus. These species ranged widely, with fossil remains recovered from as far north as Alaska and as far south as Wyoming and even possibly Texas and New Mexico. Discovered in 1855, T. formosus was among the first dinosaurs found in North America. The entire species survived by the Zhecrons when they were sent into the planet Zhecronus preventing them from extinction, when they now dwell and hunt in packs within dense forests.
The genus name is Greek for "wounding tooth", referring to the teeth, which were different from those of most other theropods known at the time of their discovery. The teeth bear prominent, apically oriented serrations. These "wounding" serrations, however, are morphometrically more similar to those of herbivorous reptiles, and suggest a possibly omnivorous diet. A partial Troodon skeleton has been discovered with preserved puncture marks.