Editing Troodon (section)

===Early research===
[[File:Troodon formosus.jpg|thumb|left|1860 illustration of the ''T. formosus'' holotype tooth]] 
The name was originally spelled ''Troödon'' (with a [[Diaeresis (diacritic)|diaeresis]]) by [[Joseph Leidy]] in 1856, which was officially amended to its current status by Sauvage in 1876.<ref>{{Cite journal
|publisher=Société géologique de France
|url=https://books.google.com/books?id=aG27AAAAIAAJ&q=tro%25C3%25B6don&pg=PA770|journal=Bulletin de la Société géologique de France|date=1876
| last = Sauvage | first=H.-E.
| issue= 3e série 4
| pages= 434–444
| title=Notes sur les reptiles fossiles
|language=fr}}</ref> The [[type (zoology)|type specimen]] of ''Troodon'' has caused problems with classification, as the entire genus is based only on one single tooth from the [[Judith River Formation]]. ''Troodon'' has historically been a highly unstable classification and has been the subject of numerous conflicting synonymies with similar theropod specimens.<ref name=Talos/>

The ''Troodon'' tooth was originally classified as a "lacertilian" ([[lizard]]) by Leidy, but reassigned as a [[megalosaurid]] dinosaur by [[Franz Nopcsa von Felső-Szilvás]] in 1901 (Megalosauridae having historically been a [[wastebin taxon]] for most carnivorous dinosaurs). In 1924, Gilmore suggested that the tooth belonged to the herbivorous [[pachycephalosaur]] ''[[Stegoceras]]'' and that ''Stegoceras'' was in fact a junior synonym of ''Troodon''. The similarity of troodontid teeth to those of herbivorous dinosaurs continues to lead many paleontologists to believe that these animals were omnivores. The classification of ''Troodon'' as a pachycephalosaur was followed for many years, during which time the family [[Pachycephalosauridae]] was known as [[Troodontidae]]. In 1945, [[Charles Mortram Sternberg]] rejected the possibility that ''Troodon'' was a pachycephalosaur thanks to its stronger similarity to the teeth of other carnivorous dinosaurs. With ''Troodon'' now classified as a theropod, the family Troodontidae could no longer be used for the dome-headed dinosaurs, so Sternberg named a new family for them, ''Pachycephalosauridae''.<ref name=sternberg1945>{{Cite journal | last1 = Sternberg | first1 = C. | year = 1945 | title = Pachycephalosauridae proposed for domeheaded dinosaurs, ''Stegoceras lambei'' n. sp., described | journal = Journal of Paleontology | volume = 19 | pages = 534–538 }}</ref>