4 Sedimentary Systems and Provenance in the Western Cordillera

This session invites contributions on sedimentary processes, depositional environments, stratigraphic frameworks, and provenance evolution across western North America. Topics may include basin analysis, source-to-sink studies, and applications of stratigraphy to energy and environmental questions.

Wednesday, 22 April 2026
8:00 AM - 12:00 PM
LMH, Fiesta Terrace Salon

Preliminary study of the diversity of the Baculitidae family in the El Rosario Formation, Salsipuedes locality of the Upper Cretaceous in Baja California, Mexico: advances in paleoenvironmental research

Paper number: 4-13
Program: Technical Sessions
Time: 11:45 AM – 12:00 PM

Authors

Abstract

The El Rosario Formation, belonging to the Upper Cretaceous, is located along the northwestern coast of Baja California, Mexico, and exhibits an extensive paleontological record of marine fauna from deep to shallow environments. Within this formation, the Salsipuedes locality preserves remains of the Baculitidae family (cephalopods belonging to the order Ammonoidea). In order to provide information that contributes to the reconstruction of the paleoenvironment of the Salsipuedes locality, a taxonomic analysis was conducted on fossil baculite specimens deposited in the Paleontological Collection of the Facultad de Ciencias, UABC. As a preliminary approach, the most conspicuous visible taxonomic characters (ornamentation, sutures, aperture, and ventral morphology) were described, given the fragmentary preservation of the material. These features allowed the determination of the most specific taxonomic categories possible. Current results indicate the presence of three genera: Baculites, Eubaculites, and Fresvillia. Due to the degree of fragmentation, in some cases it was not possible to assign specimens to more specific taxonomic categories.

To date, 44 individuals have been examined, of which 17 were identified to genus level. Based on these results, the faunal composition appears to be dominated by the genera Eubaculites and Baculites (with 8 individuals each), while Fresvillia is the least represented (with a single individual). Work is currently ongoing with all 44 individuals to achieve more precise taxonomic identifications. Once the identification process is completed, the paleoenvironment will be reconstructed through the integration of taphonomic, sedimentological, petrographic, and geochemical analyses, contributing to the characterization of the paleoenvironmental setting.

Geological Society of America Abstracts with Programs. Vol. 58, No. 3

doi: 10.1130/abs/2026CD-411022

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