Amerhippus

Amerhippus is an extinct South American horse of uncertain taxonomic identity in the genus "Equus". It is sometimes classified as a subgenus containing several extinct species of horses that lived in South America, or a single, morphologically variable extinct species Equus neogeus. 
Description.
It lived from 2.588 to 0.012 Mya. It measured roughly tall and weighed approximately . 
Distribution.
They were one of two groups of equines in South America alongside "Hippidion". Fossils have been recovered from the Tarija Formation of Bolivia, the Serranía del Perijá in Venezuela, the Chiu-Chiu Formation of Chile, the Sabana Formation of the Bogotá savanna in Colombia, and from various locations in Ecuador. 
Taxonomy.
While they have formerly been referred to as belonging to 5 separate species, this has been revised down into three, and more recently a single, morphologically variable species Equus neogeus. "Equus" first appeared in South America during the late Early Pleistocene around 1 Ma. A 2008 study of mitochondrial DNA fragments of a specimen of "E. neogeus" found it to be nested within mitochondrial lineages of "E. caballus." A close relationship to caballine horses was also supported by a 2019 morphological analysis study.