First record of Bochianites neocomiensis (Ancyloceratina, Bochianitidae) from the Valanginian of the Neuquén Basin, Argentina: Significance of the fauna and global correlation

MARIN, LUCIANA S.; VENNARI, VERÓNICA V.; LESCANO, MARINA; AGUIRRE-URRETA, BEATRIZ

CRETACEOUS RESEARCH (PRINT)

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Año: 2023 vol. 151

0195-6671

A new Valanginian ammonoid fauna from the Vaca Muerta Formation in the Neuquén Basin is describedand illustrated. It includes Bochianites neocomiensis (d’Orbigny), which is recorded for the first time in thelower Valanginian Lissonia riveroi Zone where it is associated with the Andean species L. riveroi (Lisson),and less commonly with Raimondiceras gerthi (Weaver) and Neocomites subtenuis Sayn. Above theselevels, the Olcostephanus atherstoni and Karakaschiceras attenuatus subzones, comparatively poorlyknown in southern Mendoza, are recorded. Bioevents record the transition between CC3-B nannofossilsSubzone of the lower Valanginian and the CC4-A nannofossils Subzone of the upper Valanginian. Thefinding of B. neocomiensis and N. subtenuis associated with endemic Andean faunas, and their calibrationwith calcareous nannofossils, allows establishing a much more accurate long-distance correlationbetween the Neuquén Basin and the West Mediterranean Province of the Tethys.