An updated comprehensive study of Cretaceous-Paleogene angiosperms from Argentina

GANDOLFO, M.A.; ZAMALOA, M.C.; ARCHANGELSKY, A.; ARCHANGELSKY, S.; BARREDA, V.; CUNEO, N.R.; HERMSEN, E.J.; IGLESIAS, A.; LLORENS, M.; NARVÁEZ, P.L; PASSALIA, M.; PÉREZ LOINAZE, V.; POVILAUSKAS, L.; PRÁMPARO, M.B.; PUEBLA, G.G.; QUATTROCCHIO, M.E.; ROMERO, E.J.; VALLATI, P.; WILF, P.

Mendoza

Congreso; 4th International Palaeontological Congress; 2014

IANIGLA/CCT-CONICET-Mendoza

Today, the angiosperms constitute the largest clade of seed plants with more than 300,000 species worldwide distributed. They are found on every continent including Antarctica and in all types of terrestrial and even marine environments. During the last decade and with the advent of molecular biology techniques, major advances have occurred for elucidating their origin and evolution; however, there are still many aspects of their evolutionary life that remain enigmatic. Paleobotanists have long recognized that the plant fossil record is incomplete and therefore biased; nevertheless, it is the only tangible evidence of angiosperm presence throughout time contribution the backbone of information towards our understanding of their origin, life habits, history, radiation and diversification. The majority of data on fossil angiosperms comes from the Northern Hemisphere because it has been intensively studied, whereas the Southern Hemisphere?s paleofloras, in contrast, have been understudied and are in generally poorly understood. Nevertheless, sedimentary rocks from Argentina, southern South America offer a wealth of angiosperm floras that are providing critical data for addressing some of those questions. Herein, we present a comprehensive review of the fossil record (pollen grains and plant remains) of the angiosperms that inhabited Argentina from their first appearance during the late Barremian (earliest Early Cretaceous) to the Cretaceous-Paleogene (Danian) boundary. Data were gathered from 24 formations outcropping in Salta, Mendoza and San Luis provinces, and Patagonia. This review covers micro and macrofossil remains, and it consists of a detailed report on the alpha taxonomy with the major goal of identifying: 1- what taxonomical groups (based on APGIII) were dominant at what times, 2- the development (components) of plant communities, and 3- an interpretation of the environments in which they lived. The angiosperm fossil record of Argentina indicates that members of the ANITA grade, Chloranthales, and several monocots were already present during the Aptian-Albian; by the Cenomanian to the Campanian, the monocots, the eudicots (including members of the core eudicots) and the rosids (rosid I and II) became more diverse and similar to extant genera, while clearly by the Paleocene the asterids are already members of the paleocommunities.