Original paper
The Upper Tithonian–Lower Berriasian ammonite succession of Cajón de Almanza (Vaca Muerta Formation, Neuquén Basin, Argentina)
Parent, Horacio; Garrido, Alberto C.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 316 Heft 3 (2026), p. 347 - 365
81 references
published: Feb 3, 2026
published online: Jan 21, 2026
manuscript accepted: Dec 19, 2025
manuscript received: Oct 14, 2025
DOI: 10.1127/njgpa/1299
ArtNo. ESP155031603007, Price: 29.00 €
Abstract
The exposures of the Tithonian–Berriasian succession of the Vaca Muerta Fm in Cajón de Almanza (Neuquén Basin) are extensively covered by modern material. This condition hampers the bed by bed collection of ammonites which, consequently, have never been sampled as successions of assemblages. The fine preservation and abundance of the local fauna makes of Cajón de Almanza a locality of choice for expanding the knowledge of Tithonian–Berriasian ammonite fauna and its succession in this deep sector of the basin. Recently we have collected small assemblages from three successive horizons within the interval Altenans-Damesi zones (upper Tithonian–upper Berriasian). These ammonites belong to Catutosphinctes inflatus (Leanza), Corongoceras mendozanum (Behrendsen), Leonardia almanzaensis n. gen., n. sp., Substeueroceras koeneni (Steuer), and Subthurmannia boissieri (Pictet). From this material plus a published list, and a number of few sets of ammonites formerly collected in isolation, we have pieced together a new chronostratigraphic and palaeontologic scheme for the study area, including the confirmation of the stratigraphic position of the holotype of Pliosaurus almanzaensis O’Gorman, Gasparini & Spalletti in the upper Alternans Zone. urn:lsid:zoobank.org:pub:3C5F2E03-C06B-4358-A2D1-967ABC63D06E
Keywords
Andean ammonites • Tithonian • Berriasian • Cajón de Almanza • Leonardia almanzaensis n. gen., n. sp.