Maastrichtian palynological assemblages from the Chorrillo Formation, Patagonia, Argentina

The Chorrillo Formation is an uppermost Cretaceous continental sequence cropping out in the southernmost re-gion of Patagonia. Recent field trips carried out in the region allowed the recognition of a highly diverse record of continental vertebrates, invertebrates, and plants that inhabited the region during the latest Cretaceous. In this study, a palynological analysis derived from an exhaustive sampling in the unit is presented. The recovered taxa include 44 spore species, 28 gymnosperm and 55 angiosperm pollen taxa, as well as 7 algae, and fungal re-mains. Two new taxa of unknown affinities (Acylomurus silviae sp. nov. and Lusatisporis choiols sp. nov.) and a new alga (Sphaeroplea striatocristata sp. nov.,) are proposed. Taxonomic composition of the palynological assem-blages suggest humid and temperate to warm climatic conditions. Based on the stratigraphic range of the iden-tified taxa, a Maastrichtian age is suggested, coincident with previous interpretations derived from the stratigraphic relationships of the Chorrillo Formation. Comparisons with other latest Cretaceous to Danian assemblages from southern Gondwana, carried out using multivariate statistical methods, indicate that the assemblage from the Chorrillo Formation has greatest similarities with the palynological assemblages of the Maastrichtian La Irene and La Anita formations, the upper levels of the Monte Chico Formation, and with the Maastrichtian levels of the Lefipan Formation, all units cropping out in central and southern Patagonia.(c) 2023 Published by Elsevier B.V.