(ornament horned face).
Named By: S. D. Sampson, M. A. Loewen, A. A. Farke, E. M. Roberts, C. A. Forster, J. A. Smith & A. L. Titus - 2010.
Classification: Chordata, Reptilia, Dinosauria, Ornithischia, Ceratopsidae, Chasmosaurinae.
Species: K. richardsoni (type).
Size: About 4.5 meters long.
Known locations: USA, Utah - Kaiparowits Formation.
Time period: Campanian of the Cretaceous.
Fossil representation: Almost complete skull and mandible (jaw), as well as partial post cranial skeletal remains including vertebrae, ribs, hip and a partial rear leg.
in 2010, Kosmoceratops has quickly become a
favourite, thanks largely to the highly ornate form of the skull,
which was also the inspiration for the genus name. To start, the
frill section of the skull is twice as wide as it is long, which by
physical proportions, means that it is among the shortest known
frills for a chasmosaurine ceratopsian
dinosaur. At the top of the
frill there are ten small horns, the central eight of which curve
down and towards the braincase, while the two horns on the end
project to the sides. The nasal horn is low and laterally compressed
so that it forms more of a blade like structure, and in the holotype
is noted as having a blunt tip. Perhaps most interesting though are
the brow horns that grow from above the eye sockets. Usually,
ceratopsians that have brow horns are noted as curving either forwards
or backwards, but in Kosmoceratops the horns
actually project out to
the sides, and Kosmoceratops is a rare example of
this is yet further evidence that the horns and frills of ceratopsian
dinosaurs were more for species recognition and display rather than
The reason for the highly ornate form of Kosmoceratops seems to have been a result from living in a restricted habitat. Not long after the chasmosaurine ceratopsians appeared in Laramidia, they seem to have become isolated in northern and southern populations due to geological barriers in central Laramidia. It was not until these barriers disappeared later in the Cretaceous that northern and southern populations mixed. Before this time, limited gene pools within the restricted populations would have allowed for a greater chance of elaborate skull designs than that typically seen in larger populations that usually ‘water down’ the appearance of unique physical characteristics.
Kosmoceratops is known to have shared it’s habitat with another chasmosaurine ceratopsian named Utahceratops, while a slightly more distantly related centrosaurine ceratopsian called Nasutoceratops is also present. Hadrosaurs such as Parasaurolophus and Gryposaurus are also present, while the main predatory threats to Kosmoceratops would include tyrannosaurs such as Teratophoneus and when younger troodonts such as Talos.
- New horned dinosaurs from Utah provide evidence for intracontinental dinosaur endemism. - PLoS One 5(9):e12292 . - S. D. Sampson, M. A. Loewen, A. A. Farke, E. M. Roberts, C. A. Forster, J. A. Smith & A. L. Titus - 2010.