| Named By: | Mark Norell, James Clark, Alan Turner, Peter Makovicky, Rinchen Barsbold & Timothy Rowe in 2006 |
| Time Period: | Late Cretaceous, 75 Ma |
| Location: | Mongolia, omnogovi Province - Djadokhta Formation |
| Size: | Estimated to be around 2 meters long |
| Diet: | Carnivore |
| Fossil(s): | Skull and cervical (neck) vertebrae and shoulder girdle |
| Classification: | | Chordata | Reptilia | Dinosauria | Saurischia | Theropoda | Deinonychosauria | Dromaeosauridae | Velociraptorinae | |
Tsaagan (meaning "white") is a genus of carnivorous dromaeosaurid theropod dinosaur from the Djadokhta Formation of the late Cretaceous of Mongolia.
The fossil of Tsagaan was discovered in 1996 and first identified as a specimen of Velociraptor. After a CAT-scan in May 1998 it was concluded that it represented a new genus. In December 2006 its type species was named and described by Mark Norell, James Clark, Alan Turner, Peter Makovicky, Rinchen Barsbold and Timothy Rowe. The species name, Tsaagan mangas, should be read as a whole with the generic name qualifying the specific epithet, and is derived from the Mongolian words for "white monster" (tsagaan mangas), although with an accidental misspelling of the word Tsagaan.
The holotype specimen, IGM 100/1015, was found near Xanadu in Omnogovi Province in layers of the Djadokhta Formation dating to the Campanian, about 75 million years ago. It consists of a well-preserved skull and series of ten neck vertebrae as well as a damaged left shoulder girdle. It is the only specimen found of Tsaagan and belonged to an adult individual.
Tsaagan was a medium-sized dromaeosaurid. In 2010 Gregory S. Paul estimated its length at 2 metres (6.6 ft), its weight at 15 kilograms (33 lb). The skull in general appearance resembles that of Velociraptor but differs from it in many details. It is more robust and smooth on top; unique derived traits, autapomorphies, include long paroccipital processes and basipterygoids at the back of the skull and a jugal touching the squamosal.