A description of a new species of Brachypteracias (Family Brachypteraciidae) from the Holocene of Madagascar

A single humerus of a ground-roller (Brachypteracias, Family Brachypteracii dae), a family endemic to Madagascar, found at a subfossil site in the sout hwest (Ampoza) of presumed Holocene age and outside the modern geographic r ange of this genus, is described as a new species. Currently, the region ar ound Ampoza is dry deciduous forest and does not contain any species of gro und-roller. On the basis of the habitat preferences of the two extant speci es of Brachypteracias, both occurring in humid forests, as well as other su bfossils recovered at Ampoza, it is concluded that the region was once more mesic. The commencement of this period of desiccation in southwestern Mada gascar and associated ecological change occurred before human colonization of Madagascar some 2 000 years ago.