Maastrichtian palynological assemblages from the Chorrillo Formation, Patagonia, Argentina

PEREZ LOINAZE, VALERIA S.; VERA, EZEQUIEL I.; MOYANO-PAZ, DAMIAN; CORONEL, MARINA D.; MANABE, MAKOTO; TSUIHIJI, TAKANOBU; NOVAS, FERNANDO E.

REVIEW OF PALAEOBOTANY AND PALYNOLOGY

ELSEVIER SCIENCE BV

Año: 2023

0034-6667

The Chorrillo Formation is an uppermost Cretaceous continental sequence cropping out inthe southernmost region of Patagonia. Recent field trips carried out in the region allowed therecognition of a highly diverse record of continental vertebrates, invertebrates, and plantsthat inhabited the region during the latest Cretaceous. In this study, a palynological analysisderived from an exhaustive sampling in the unit is presented. The recovered taxa include 44spore species, 28 gymnosperm and 55 angiosperm pollen taxa, as well as 7 algae, andfungal remains. Two new taxa of unknown affinities (Acylomurus silviae sp. nov. andLusatisporis choiols sp. nov.) and a new alga (Sphaeroplea striatocristata sp. nov.,) areproposed. Taxonomic composition of the palynological assemblages suggest humid andtemperate to warm climatic conditions. Based on the stratigraphic range of the identified taxa, a Maastrichtian age is suggested, coincident with previous interpretations derived fromthe stratigraphic relationships of the Chorrillo Formation. Comparisons with other latestCretaceous to Danian assemblages from southern Gondwana, carried out using multivariatestatistical methods, indicate that the assemblage from the Chorrillo Formation has greatestsimilarities with the palynological assemblages of the Maastrichtian La Irene and La Anitaformations, the upper levels of the Monte Chico Formation, and with the Maastrichtian levelsof the Lefipán Formation, all units cropping out in central and southern Patagonia