Abstract

CACCAVARI, Marta A.  and  GULER, M. Verónica. Acaciapollenites acaciae sp. nov., a new mimosoid polyad species from the Neogene of Colorado Basin, Argentina. Ameghiniana [online]. 2006, vol.43, n.3, pp.585-590. ISSN 1851-8044.

Fossil mimosoid polyads have been recently recovered from Neogene deposits in the Colorado Basin, Argentina, and the new species Acaciapollenites acaciae sp. nov. is described, which is closely similar to polyads of species included in Acacia Miller subgenus Acacia Vassal. It is characterized by colporate apertures on the distal face of the pollen grains, a typical polyad of the subgenus Acacia. The new polyad species is very similar to those of the extant Acacia curvifructa Burkart. Comparing the habitat of subgenus Acacia extant species, the Acaciapollenites acaciae occurrence suggests drier and warmer paleoclimatic conditions than today for the Late Miocene-Early Pliocene in the Colorado Basin. Paleogeographic data of Acacia pollen diversity are discussed. A similar early diversification and distribution of Acacia genus is recognized for the New and Old World.

Keywords : Acacia polyads; Neogene; Colorado Basin; Argentina.