(Bison horn face).
Named By: Christopher J. Ott & Peter L. Larson - 2010.
Classification: Chordata, Reptilia, Dinosauria, Ornithischia, Ceratopsia, Ceratopsidae, Chasmosaurinae.
Species: T. sacrisonorum (type).
Size: Uncertain due to lack of remains.
Known locations: USA, South Dakota - Hell Creek Formation.
Time period: Maastrichtian of the Cretaceous.
Fossil representation: Single partial skull.
The Tatankaceratops type specimen was pieced together from partial remains before it was named in 2010, and soon after there were murmurings that it was actually a juvenile Triceratops. This stems down to a 2011 study by Nicholas R. Longrich which noted a mix of juvenile and adult characteristics in the skull. Since this time other palaeontologists have expressed their suspicions about Tatankaceratops with the two main theories being that it is either a juvenile Triceratops or one that has a growth defect that stunted its development.
- A New, Small Ceratopsian Dinosaur from the Latest Cretaceous Hell Creek Formation, Northwest South Dakota, United States: A Preliminary Description. - Christopher J. Ott & Peter L. Larson. - In, New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, Bloomington, Indiana University Press - M. J. Ryan, B. J. Chinnery-Allgeier & D. A. Eberth - 2010.
- Titanoceratops ouranos, a giant horned dinosaur from the Late Campanian of New Mexico. - Cretaceous Research. 32 (3): 264–276. - Nicholas R. Longrich - 2011.
- Triceratops with a kink: Co-ossification of five distal caudal vertebrae from the Hell Creek Formation of North Dakota. - Cretaceous Research, 108 (2020): 104355. - Matthew M. Canoy Illies & Denver W. Fowler - 2011.