Diversity and community structure of the late Pleistocene mammal fauna of North America.

Holocene reduction in diversity is partially the result of a megafaunal extinction but higher diversity of the late Pleistocene small mammal communities is caused by the association of extant species that appear to be ecologically imcompatible today. These disharmonious faunas reflect more equable climates with environmental and diversity gradients that delimit faunal zones. The geologically young communities of today cannot be applied as direct analogs in the reconstruction of late Pleistocene environments. -from Author