(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.