Espíritu Santo antelope squirrel

The Espíritu Santo antelope squirrel, Ammospermophilus insularis, is a species of antelope squirrel in the family Sciuridae that is endemic to Mexico, where it is known from the island of Espíritu Santo in the Gulf of California and also inhabits Isla San Marcos. Edward William Nelson and Edward Alphonso Goldman described it in 1909 as a subspecies of the white-tailed antelope squirrel, and Arthur H. Howell raised it to full species in 1938 because of its slightly larger skull and the absence or reduction of the third upper premolar. It inhabits rocky desert environments in Baja California Sur, from sea level to about 600 meters. Its taxonomic status is disputed: a 2007 comparison of DNA and morphology suggested it is a subspecies of the white-tailed antelope squirrel, and since 2008 the IUCN has recognized it as such.