First quaternary Brazilian cave pollen record: Morphological descriptions, taxonomic and ecological data

Abstract

This paper presents descriptions, and taxonomic and ecological data by the angiosperm pollen grains recovered from Quaternary sediments of the Gruta do Urso Cave, Tocantins State, Northern Brazil. Among recovered assemblage, 44 types of angiosperm pollen were identified. Most of the pollen types described here are related to the modern aboreal-shrub and herbaceous-subshrub taxa currently present in the plant communities of the Cerrado biome: (i) forest formations (Annonaceae, Aspidosperma, Ilex, Celtis, Trema, Tournefortia, Protium, Combretaceae-Melastomataceae type, Croton-type, Moraceae-Urticaceae type, cf. Bauhinia brevipes, Cassia, Pithecellobium, Peixotoa, and Cedrela); (ii) savannah formations (Anacardium, Astronium, Asteraceae Tribu Eupatorieae, Caryocar, Cyperaceae, Eriotheca-type, Ludwigia, Pseudobombax spp., Ouratea, Qualea, and Utricularia), and (iii) grasslands (Poaceae). Regarding the diversity of pollen types registered, the most representative botanical families were: Fabaceae (8), Malvaceae (4), Euphorbiaceae (3), Anacardiaceae (3), Apocynaceae (2), Cannabaceae (2), Sapindaceae (2) and Poaceae (2), which also occur in the Cerrado-Caatinga transition. Pollen data show paleovegetation during the Last Glacial Maximum and Holocene times out of the cave, and provides a reliable source for paleoecological, paleoenvironmental and paleoclimatic investigations.