The gymnosperm pollen Shanbeipollenites proxireticulatus Schrank from the Vaca Muerta Formation (Upper Jurassic–Lower Cretaceous), Neuquén Basin, Argentina

OLIVERA, DANIELA E.; MARTÍNEZ, MARCELO A.; ZAVALA, CARLOS; OTHARÁN, GERMÁN; MARCHAL, DENIS; KÖHLER, GUILLERMINA

CRETACEOUS RESEARCH (PRINT)

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Año: 2018 vol. 90 p. 120 - 130

0195-6671

This study documents for the first time the occurrence of Shanbeipollenites proxireticulatus Schrank inlevels of the Vaca Muerta Formation, Neuquen Basin, Argentina. It represents the first record of thisspecies in high latitudes of the Southern Hemisphere. The Argentinian specimens are associated withuseful palynostratigraphical indicators which suggest an early Valanginian age for the palynoflorayielding S. proxireticulatus. Therefore, this finding constitutes the first record from the Cretaceous. Thistaxon is related to the orders Cycadales/Bennettitales/Ginkgoales. During the Cretaceous in Patagoniacycads and bennettitaleans groups show marked adaptations to warm and strongly seasonal dry climateperiodically influenced by volcanic activity. The paleogeographic distribution of the records ofS. proxireticulatus, symmetrically located on both sides of the equator, together with its relationship withthe climate zones or Biomes, suggest that the parental plants of this pollen grain thrived under warmclimate and probably stressed paleoenvironmental conditions. Since the studied sample is located near1000 m below the Intravalanginian unconformity, and older age (i.e. late Berriasian) cannot be discarded.