Short-Tailed Opossums Genus Monodelphis: Patterns of Phenotypic Evolution and Diversification

Abstract

Monodelphis comprises one of most speciose genera of living marsupials, with 24 described species that inhabit the litter layer and other ground-level microhabitats. Different of most other American marsupial taxa restricted to humid forest or drier habitats, short-tailed opossums are found in a wide range of environments, including lowland rainforest, open vegetation areas, temperate grasslands, and high-altitude landscapes from eastern Panama to northern Argentina. In landmasses with an extremely high diversity of environments, such as South America, few groups are widespread at a continental scale. But what makes Monodelphis special, allowing its success in so many habitat types? The answer to this question might lie, at least partially, in its extraordinary phenotypic diversity. No other group of New World marsupials has developed more extreme variation in morphological characters and remarkable behavioral distinctions as observed in short-tailed opossums, much of which still needs to be properly documented. This chapter provides an overview of the current knowledge on the evolution of the striking variety of coat colors observed in this diverse group and on their spatial and temporal patterns of diversification.KeywordsBiogeographyCoat-color evolutionHabitat occupancyNeotropical marsupialsSouth America