INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Cretaceous macroflora from Sandwich Bluff Member, Vega Island, Antarctic Peninsula
Autor/es:
ARI IGLESIAS; JOSE O´GORMAN; PIPO, L.; CARDENAS, M.; RODOLFO CORIA
Lugar:
General Roca
Reunión:
Congreso; Congreso de la Asociación Paleontológica Argentina; 2016
Institución organizadora:
Asociación Paleontológica Argentina
Resumen:
A new late Maastritchian macroflora from the Sandwich Bluff Member (López de BertodanoFormation), located at Cape Lamb, Vega Island is communicated. The complete fossilbearingstratigraphical section is represented by a progradational near-shore marineenvironment. Although macrofloristic records are previous known, these were based only onbroad leaves assigned to Araucaria fibrosa Césari et al., 2009. Previous palynologicalanalyses have also recorded Lycophytes, Cyateaceae, Osmundaceae, Polypodiaceae,Podocarpaceae, Proteaceae, Nothofagaceae, and several unidentified angiosperms. The smallsample collected contains a well preserved new macroflora. A single pinna is assigned to thefern cf. Marattiopsis vodrazkae Kvacek, 2014 (Marattiaceae), formerly recorded for theearliest Campanian Hidden Lake Formation. Among angiosperms, four small-sized(nanophyll) and dentate leaf morphotypes were identified. The angiosperm leaves likelycorrespond to a new, unrecorded species for the James Ross Basin. A mature fossil cupule(woody flower involucre) consisting of four woody valves that are fused at their bases andpartially preserve lamellae rows and cuticle, could be assigned to Nothofagaceae. This fossilencompasses the rich Nothofagaceae pollen record with three of the subgenera pollen-typesfrom the late Campanian of the James Ross Basin (Snow Hill Island Formation). In summary,the new macroflora is in accordance with an important floristic change at the late CampanianearlyMaastrichtian, which was supported by the palynological record of the AntarcticPeninsula. The floristic change can be associated to climatic shifting, although some plantfamilies persist even into the Antarctic Paleogene temperate forests.