Registro fósil y distribución de Anadenathera en Argentina desde el Mioceno hasta la actualidad

Abstract

Currently Fabaceae, is one of the dominant families of the Seasonally Dry Tropical Forests or Neotropical seasonal dry forests. Anadenanthera which integrates the family, has wide geographical distribution in South America and the West Indies, but in Argentina it`s only present Anadenantera colubrina var. cebil in the north and their records are represented from the Miocene to the present through palynomorphs and mineralized woods. The main objective of this work is to contribute to the understanding in the context of the history of Anadenanthera during the Neogene and Quaternary in Argentina, on the basis of the review and integration of the paleobotanical history, geological and climatic available that have affected the genre in the country. Studied fossil materials come from different geological formations of Argentina: Chenque Formation (Miocene), Parana Formation (Middle Miocene), San Jose Formation (Middle Miocene), Ituzaingo Formation (Pliocene) and Ibera (Holocene). The material found on the Chenque Formation is referred to Polyadopollenites coincides with the described material for the Middle Miocene of the central-eastern Argentina and the Pliocene of northeast Argentina. On the other hand in Parana and Ituzaingo Formation studied sample of mineralized woods of Anadenantheroxylon villaurquisense , finally the sample found in Holocene of Ibera Corrientes Province corresponds to Anadenanthera colubrina var. macrocarpa . With these data it can be concluded that Anadenathera had a wide geographical record in Miocene and Holocene of Argentina, it was found in sediments from the lower Miocene of Patagonia by integrating a Subtropical Paleoflora. From the Middle-Upper Miocene integrated the vegetation in northeast Argentine constituting xerophiles forests. Their last record is equivalent to the Middle Holocene of sediments from Ibera integrating the regional vegetation and indicating an open vegetation characteristics of dry environments. Finally it`s noteworthy that the spatial and temporal succession of Anadenanthera in Argentina, would have been intimately associated with tectonic and climatic events occurred during the Neogene and Quaternary.