Taxonomic update on Astacodes sp. (Crustacea: Palinuridae) from the Lower Cretaceous of Guerrero, Mexico

Actualización taxonómica en Astacodes sp. (Crustacea: Palinuridae) del Cretácico Inferior de Guerrero, México

Oscar González-León1,*, Francisco J. Vega2

1 Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, 54090, Estado de México, México.

2 Instituto de Geología, Universidad Nacional Autónoma de México. Ciudad Universitaria, Coyoacán, 04510, CDMX, México.

* Corresponding author: (O. González-León) This email address is being protected from spambots. You need JavaScript enabled to view it. 

How to cite this article:

González-León, O., & Vega, F. J. (2026). Taxonomic update on Astacodes sp. (Crustacea: Palinuridae) from the Lower Cretaceous of Guerrero, Mexico. Boletín de la Sociedad Geológica Mexicana, 78(1), A230925. https://doi.org/10.18268/BSGM2026v78n1A230925 

Manuscript received: August 29, 2025. Corrected manuscript received: September 18, 2025. Manuscript accepted: September 23, 2025.

ABSTRACT

A reexamination of the specimen originally described as Astacodes sp. cf. maxwelli (Stenzel, 1945) from the San Lucas Formation in southwest Mexico, allows us to consider it as Astacodes cf. falcifer based on morphologic criteria closer to Astacodes falcifer from Speeton, England and Neuquén, Argentina. Recognizing the reproductive structures known as gonopores and poorly preserved gonopods allowed a reinterpretation of the Mexican specimen as a male. Sexual dimorphism criteria in this taxon could help resolve taxonomic issues to differentiate between males and females, using sex-specific morphological characteristics, (ornamentation, size, sternum shape, among others). These characteristics can also help compare and differentiate it from other species.

Keywords: Astacodes cf. falcifer, San Lucas Formation, Lower Cretaceous, sexual dimorphism.