Troodontidae
Saurischia Theropoda Tetanurae Coelurosauria Troodontidae [Carnivore]
Verry small long-legged theropods with large brains, highly pneumatic skulls, many teeth and retractable second-toe claws.
Although troodontids have autapomorphies that eliminate them from consideration as bird ancestors, they are nevertheless one of the closest avian outgroups within the Theropoda. (Currie, P.J. and Dong Z. (2001) New information on Cretaceous troodontids (Dinosauria, Theropoda) from the People\\\'s Republic of China Can. J. Earth Sci./Rev. Can. Sci. Terre 38(12): 1753-1766)
Cretaceous Early
US
Geminiraptor suarezarum - Cedar Mountain Formation
China
Jingfengopteryx elegans -
Mei long - Yixian Formation
Sinovenator changii - Yixian Formation, [Jiufotang Formation], Liaoning
Sinusonasus magnodens - Yixian Formation, Western Liaoning
Cretaceous Late
Canada
Paronychodon lacustris - ?Judith River Formation (Wedge), Alberta
Troodon
Polyodontosaurus grandis - Belly River Formation, Alberta
Troodon formosus - Horseshoe Canyon Formation, Judith River Group (Wedge), Alberta
Mexico
Troodon
Troodon formosus - \\\"El Gallo\\\" Formation
US
Paronychodon lacustris - Judith River Formation (Wedge), Montana; Hell Creek Formation, Montana; Lance Formation, Wyoming; Fruitland Formation, New Mexico; Laramie Formation, Colorado
Aublysodon explanatus - Judith River Formation (Wedge), Montana
Deinodon explanatus - Judith River Formation (Wedge), Montana
Dipriodon caperatus - Laramie Formation, Colorado
Dromaeosaurus explanatus - Judith River Formation (Wedge), Montana
Dryptosaurus explanatus - Judith River Formation (Wedge), Montana
Laelaps explanatus - Judith River Formation (Wedge), Montana
Meniscoessus\\\"\\\" caperatus - Laramie Formation, Colorado
Paronychodon caperatus? - Laramie Formation, Colorado
Paronychodon explanatus? - Judith River Formation (Wedge), Montana
Tripriodon caperatus - Laramie Formation, Colorado
Triprotodon carperatus - Laramie Formation, Colorado
Zaphsalis abradus [sic] - Judith River Formation (Wedge), Montana
Zapsalis abradens - Judith River Formation (Wedge), Montana
Talos sampsoni - Kaiparowits Formation, Utah
Troodon
Troodon formosus - Judith River Formation (Wedge), Hell Creek Formation, Montana, Lance Formation, Wyoming
China
Linhevenator tani - Wulansuhai Formation
Philovenator curriei - Wulansuhai Formation
Xixiasaurus henanensis - Majiacun Formation
Mongolia
Borogovia gracilicrus - Nemegt Formation
Byronosaurus jaffei - Ukhaa Tolgod
Saurornithoides mongoliensis - Djadochta Formation
Zanabazar junior - Nemegt Formation
Saurornithoides junior - Nemegt Formation
Tadzhikistan
Troodon
Troodon isfarensis - Yalovach Formation
Uzbekistan
Troodon
Troodon asiamercanus - Khodzhakul\\\' Formation
Urbacodon itemirensis - Dzharakuduk Formation