Kosmoceratops

Kosmoceratops () is a genus of ceratopsid dinosaur that lived in North America about 76–75.9 million years ago during the Late Cretaceous period. Specimens were discovered in Utah in the Kaiparowits Formation of the Grand Staircase–Escalante National Monument in 2006 and 2007, including an adult skull and postcranial skeleton and partial subadults. In 2010, the adult was made the holotype of the new genus and species Kosmoceratops richardsoni; the generic name means "ornate horned face", and the specific name honors Scott Richardson, who found the specimens. The find was part of a spate of ceratopsian discoveries in the early 21st century, and Kosmoceratops was considered significant due to its elaborate skull ornamentation.

Kosmoceratops had an estimated length of and a weight of . As a ceratopsid, it would have been quadrupedal with a heavily constructed skeleton. It had a triangular beak with a pointed tip and a blade-like nasal horn with a flattened upper portion. While the horns above the eyes were oriented forwards or hindwards in most of its relatives, the horns of Kosmoceratops pointed up and to the sides, then downwards, ending in pointed tips. The neck frill was short from front to back, with small (openings through the frill), and ten hook-like on the hind margin, with eight curving forwards and two curving to the sides. With fifteen well-developed horns and horn-like structures, it possessed the most ornate skull of any known dinosaur species. Kosmoceratops was a chasmosaurine ceratopsid and was originally suggested to be closely related to Vagaceratops (which also had forward-curving epiossifications on the back of the frill) but this has been debated, some authors finding the latter closer to Chasmosaurus. Kosmoceratops is also considered closely related to Spiclypeus, which had a similar frill.