Bullatosauria
Bullatosauria refers to the clade of arctometatarsalian theropods recognized originally by Kurzanov (1976) then by Currie (1985), and formalized by Holtz (1994), who later (Holtz, 1996) clarified it to represent a node-based clade including Ornithomimus and Troodon (=Stenonychosaurus) and all descendants of there most recent common ancestor. The term Bullatosauria (Latin bullatus, meaning inflated) refers to the bulbous parasphenoid capsule beneath and behind the orbit which is considered a valid synapomorpy that unites the clade.