Troodon was erected based on a tooth. Teeth are rarely diagnostic features in reptiles. Hence, teeth are usually referred to as “cf (insert genus name here)” in scientific literature. It is also true that Troodon is badly lumped; containing many different genera that are at this time considered species of Troodon. read more
Troodon (/ ˈ t r oʊ. ə d ɒ n / TROH-ə-don; Troödon in older sources) is a dubious genus of relatively small, bird-like dinosaurs known definitively from the Campanian age of the Cretaceous period (about 77 mya). It includes at least one species, Troodon formosus, known from Montana. read more