Review of the Origins and Biogeography of Bats in South America

Burton K. Lim

Abstract


In spite of the fact that South America was an insular continent for most of the Tertiary, it has the highest species diversity for many organismal groups, including bats. However, the colonization of South America by bats has been poorly studied, even though they are the second most speciose order of mammals. A review of taxonomy, systematics, distribution, and the fossil record suggest that there were several dispersals to South America within 3 superfamilies of bats (Emballonuroidea, Noctilionoidea, and Vespertilionoidea). The reconstruction of ancestral areas based on a phylogeny of bats infers that Africa is the geographic area of origin for most basal nodes. This implies that the diversification of Neotropical species in Noctilionoidea occurred after a single colonization of South America from Africa in the Eocene by an ancestor of the New World families Furipteridae, Mormoopidae, Noctilionidae, Phyllostomidae, and Thyropteridae. Within Emballonuroidea, a similar trans-Atlantic dispersal in the Oligocene gave rise to the New World tribe Diclidurini in the family Emballonuridae. The situation for Vespertilionoidea is more complex with multiple dispersals in 3 families (Molossidae, Natalidae, and Vespertilionidae). For Molossidae, there are hypothesized 5 dispersals to South America from Africa beginning in the Eocene but the exact timing and origin of these colonizations are uncertain because of the lack of comprehensive phylogenies for the family and an incomplete fossil record. Similarly for Vespertilionidae, the higher- level relationships are poorly resolved and supported but there were 3 independent dispersals to South America from North America within the subfamily Myotinae and at least 2 dispersals from North America and 1 dispersal event from Africa for the tribes of the subfamily Vespertilioninae. In Natalidae, the family originated in North America and colonized the West Indies with a subsequent dispersal probably during the Pliocene that gave rise to 2 species in South America. After the establishment of the Panamanian land connection, there were more recent overland dispersals from North America to South America for several species of bats, but many species in different lineages also expanded their distributional ranges in the opposite direction. Although general hypotheses of the origin of bats in South America can be inferred based on previous phylogenetic studies, as new palaeontological data are discovered and comprehensive phylogenies are proposed for more groups, the details of historical biogeography, modes of speciation, and times of diversification will be better resolved and corroborated.


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