Amargastegos (meaning "covered being from La Amarga") is a dubious genus of extinct stegosaurid ornithischian dinosaur. The type species and only current species is A. brevicollus, the species name derived from the unique trait of short cervical vertebrae. Amargastegos is one of few genera of stegosaurid from the Southern Hemisphere, along with traces from Bolivia and the South African genus Paranthodon. The new name is registered in the Official Registration of Zoological Nomenclature, or Zoobank, a requirement for validity. The Amargastegos holotype and only specimen, MACN N-43, comes from the La Amarga Formation of Argentina, and dates specifically to the boundary of the Barremian and Aptian, about 125 mya. It includes some dorsal osteoderms, the cervical and caudal vertebrae, and one s