Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon

  Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon Abstract Snakes exhibit extreme cranial kinesis that facilitates ingestion of prey with large cross-sectional area, but this ability is widely predicted to reduce bite performance due to decreased structural rigidity. Consequently, most large-bodied snakes rely on envenomation or constriction to subdue prey prior to ingestion. Species within the genus Drymarchon represent a notable exception: these large, non-venomous, non-constricting snakes routinely consume a wide range of prey, including large and potentially dangerous vertebrates, using only simple seizing and pinioning behaviors. Here, we quantify bite performance in three species of Drymarchon ( D. corais, D. couperi, and D. melanurus ), examine morphological predictors of biting performance, compare biting pressure to constriction pressure in similarly sized snakes, and synthesize dietary records across the genus. Our results sh...

Integrative taxonomy unveils a new lineage within Acanthogonatus centralis Goloboff, 1995 (Araneae, Mygalomorphae, Pycnothelidae): description of Acanthogonatus monicae sp. nov. from central Argentina

 


Integrative taxonomy unveils a new lineage within Acanthogonatus centralis Goloboff, 1995 (Araneae, Mygalomorphae, Pycnothelidae): description of Acanthogonatus monicae sp. nov. from central Argentina

Abstract

A new species of Pycnothelidae Chamberlin, 1917 from the Pampean mountain ranges, Córdoba, Argentina is described and illustrated: Acanthogonatus monicae sp. nov. Here, we combine morphological analyses, molecular phylogeny based on the COI gene, species delimitation methods (bPTPABGD), and ecological niche modeling. These approaches consistently support two independent evolutionary lineages previously assigned to A. centralis Goloboff, 1995. The new species is morphologically similar to A. centralis and A. parana Goloboff, 1995, but differs from both by genitalic characters in males and females. Additionally, an updated identification key for Argentine species of Acanthogonatus is provided.

Signorotto F, Ferretti N (2026) Integrative taxonomy unveils a new lineage within Acanthogonatus centralis Goloboff, 1995 (Araneae, Mygalomorphae, Pycnothelidae): description of Acanthogonatus monicae sp. nov. from central Argentina. Evolutionary Systematics 10(1): 31-46. https://doi.org/10.3897/evolsyst.10.172168