Caracterización de las provincias fitogeográficas triásicas del Gondwana extratropical

ARTABE, A.; MOREL, E.; SPALLETTI, L.

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2003 vol. 40 p. 387 - 405

0002-7014

The Triassic distribution of plants in Gondwanaland is analyzed and the major biogeographic units -realm, areas and provinces- are defined using a taxonomic criterion. The Triassic Gondwana Realm with the ?DicroidiumFlora? is characterized by Corystospermaceae and typical endemic genera; the endemism also appear in pan-global genera with species restricted to Gondwanaland. This first-rank unit may be divided into two second-rank units: the Tropical and Extratropical areas, characterized respectively by the Onslow and Ipswich Microfloras. Also, the Extratropical area shows a significant proportion of endemic genera and species. Within the Extratropical area, the phytogeographic distribution of distinctive suites of taxa allows to recognize two (Southwestern and Southeastern) provinces. These provinces are defined on the basis of heterogeneous and disjunct distribution of species as well as variations in biodiversity of some groups of plants. Provincialism is the result of interrelated factors, among which environmental/climatic patterns played an essential role. Thus, the Southwestern Gondwana province is related mostly with dry subtropical climate, whilst the Southeastern province developed under warm temperate and humid conditions.