When habitats change quickly, populations must migrate to more favorable situations or become extinct. Owing to the relatively short time interval, evolution was modest or minimal in most groups of land and aquatic animals. Geological Museum, Leiden, the Netherlands. Geological Museum, Leiden, the Netherlands. Land animal distribution is tied most closely to vegetation, which is the basis for the animal food chain.
Vegetation also controls visibility and mobility for animals.
In general, large heribores and their dependent large carnivores inhabit open grassland, savanna or tundra environments. Grazing in large herds and pack hunting are typical behaviors for such animals. The situation is demonstrated for the last glaciation in North America, when the distribution of land animals was much different from today. The general vegetation was a major influence on the Wisconsin faunal provinces, particularly the presence or absence of prairie openings and deciduous or conifer trees. This floral and faunal geography came to an abrupt end between 12,000 and 9000 years ago, earlier in the south and later toward the north, at the close of the last glaciation.