A new monosulcate pollen from the Early Cretaceous of central-western Argentina

Abstract

A new monosulcate species, Shanbeipollenites lagarcitensis sp. nov. is described from the Lower Cretaceous Lagarcito Formation, Sierras de Guayaguas (north-western San Luis Basin), Argentina. Shanbeipollenites lagarcitensis shares with other species of this genus a broadly ellipsoidal outline and a diagonally disposed distal sulcus. However, the new species differs from the psilate type species Shanbeipollenites quadrangulatus and from S. quadratus by the presence of sculptural elements distributed at the equatorial region, close to the opposite ends of the sulcus. The thicker wall, exine separation, much more strongly diagonal offset of the sulcus and the rugulate-verrucate sculpture with an equatorial distribution close to the opposite ends of the sulcus, distinguish this new species and expands the concept of the genus Shanbeipollenites. The presence of two separate exine layers supports its gymnosperm affinity. Furthermore, the occurrence of Shanbeipollenites lagarcitensis in the Albian Lagarcito Formation from mid–latitudes, central–western Argentina constitutes the youngest record of the genus worldwide. This new record expands the biostratigraphical range of the taxon into the Albian.

Keywords:

• Gymnosperm pollen grain
• Shanbeipollenites
• Lagarcito Formation
• Lower Cretaceous
• Argentina

Acknowledgments

Thanks to the editor and to the anonymous reviewers for their careful and constructive reviews of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Research Council of Argentina (CONICET) and with grants provided by Agencia Nacional de Promoción Científica y Tecnológica (PICT 2015-1340, N. Mego) and PIP CONICET 112 20130100444 CO (M. Prámparo).

Notes on contributors

Natalia Mego

NATALIA MEGO is a research scientist of the National Research Council of Argentina (CONICET). She obtained her Ph.D. in biology during 2010 from the Universidad Nacional de La Plata, Buenos Aires, Argentina. For her Ph.D., Natalia studied Triassic palynomorph associations from Mendoza and San Juan provinces in Argentina. Her current research interests include Cretaceous and Paleogene palynology of the San Luis Basin in central-western Argentina.

Mercedes B. Prámparo

MERCEDES B. PRÁMPARO is a Principal research scientist of the National Research Council of Argentina (CONICET). She is a member of the Palaeopalynological staff of the Argentinian Institute for Snow, Ice and Environmental Research (IANIGLA) since 1984, in Mendoza, Argentina. She has a degree in Geology and received a PhD from the Rio Cuarto University, Cordoba in 1989 for a thesis on the early Cretaceous angiosperm pollen grains and algae of a lacustrine central western Argentina basin. She has worked mainly on the Mesozoic palynology of continental and marine basins of Argentina. Her current major interests includes the biostratigraphy based on palynomorphs of the K/T boundary, Paleogene and Neogene of different basins of Argentina, Bolivia and Mexico, together with palynomorph provincialism, palaeoenvironmental and systematics of pollen, spores and dinoflagellate cysts.