The short-eared dog (Atelocynus microtis), also known as the short-eared fox or the short-eared zorro, is a unique and elusive canid species endemic to the Amazonian basin. This is the only species assigned to the genus Atelocynus.

It has many names in the indigenous languages where it is endemic, such as: cachorro-do-mato-de-orelha-curta in Portuguese, zorro de oreja corta in Spanish, nomensarixi in the Chiquitano language, and uálaca in Yucuna. Other names in Spanish are zorro ojizarco, zorro sabanero, zorro negro.

The short-eared dog's history is similar to that of the other carnivorans and many of the other terrestrial placental mammals of South America. After the formation of the Isthmus of Panama in the latter part the Tertiary (about 2.5 million years ago in the Pliocene), dogs migrated from North America to the southern continent as part of the Great American Interchange. The short-eared dog's ancestors adapted to life in tropical rainforests, developing the requisite morphological and anatomical features. Apart from its superficial resemblance to the bush dog, the short-eared dog seems not to be closely related to any fox-like or wolf-like canid (R. Burton; International Wildlife Encyclopedia, 2002). It is one of the most unusual canids. The latest systematics classifies it as a species in the tribe Canini, and its closest extant relative is probably the distant taxon, the Crab-eating Fox (Cerdocyon thous)(Pietrzak, 2007). It has 74 chromosomes (2 x 36 autosomes + one pair of sex chromosomes).