Vegetation during the Eocene-Miocene interval in central Patagonia: context of mammal evolution

BARREDA, V.; PALAZZESI, L.

The Paleontology of Gran Barranca: Evolution and Environmental Change through the Middle Cenozoic of Patagonia

Cambridge Press

Lugar: Cambridge; Año: 2010; p. 375 - 382

The major vegetation trends in the context of the mammal evolution during the Eocene-Miocene in Patagonia are analyzed on the basis of the paleobotanical and palynological records. The long-term dynamics of the vegetation were most likely controlled by the changing climatic scenario, which was in turn linked to the important paleogeographic and tectonic events. The major patterns of change in the vegetation were related to: 1- the shift from megatherm (palms, tropical vines, tree ferns) to micro-mesotherm (southern beech, gymnosperm) communities, from the Barrancan towards the Tinguirirican coeval floras and, 2- the rise to the importance of shrubby and herbaceous communities (grasses, sedges, and bushes) in extra-Andean Patagonia, from the Deseadan towards the Colhuehuapian coeval floras. Even when the major trends in the floras were linked to the establishment of communities progressively adapted to cooler and drier conditions, some megatherm and wet-loving plants prevailed, mainly during the Deseadan and Pinturan equivalent time intervals.