Palaeoenvironment associated with giant tortoises of Toropi/Yupoi Formation (Late Pleistocene 50-28 ka), Corrientes province, Argentina

摘要

Vertebrate faunas of the Mesopotamian region in Argentina provided palaeoclimatic and palaeoenvironmental information from the Pleistocene. Samples collected into a carapace of the turtle Chelonoidis lutzae and associated sediments obtained from the Toropi/Yupoi Formation (Arroyo Toropi, Bella Vista) palynologically studied for the first time. The palynomorph association includes angiosperms (Brassicaceae, Amaranthaceae, Poaceae, Sapotaceae, Fabaceae, Euphorbiaceae, Myrtaceae), Bryophyta, Pteridophyte (Microgramma squamulosa), chlorophytes (Pediastrum tetras, Botryococcus) and fungal spores (Dichomera, Phaeoseptoria sp., Phragmotrichurn sp., Agaricus sp.). Palaeoecologic requirements of these botanical groups indicate the predominance of herbaceous palaeocommunities associated with arboreal or shrubby elements and fresh waters bodies. They characterized dynamic scenarios typical of ecotonal zones under arid/semi-arid and humid warm seasonal climates during the Late Pleistocene (Last Maximum Glacial) in the Mesopotamian region.