Notes on Indian wolf spiders: IV. Transfer of species previously included in the genera Crocodilosa Caporiacco, 1947 and Geolycosa Montgomery, 1904 (Araneae: Lycosidae)

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  Notes on Indian wolf spiders: IV. Transfer of species previously included in the genera Crocodilosa Caporiacco, 1947 and Geolycosa Montgomery, 1904 (Araneae: Lycosidae) The enigmatic Crocodilosa Caporiacco, 1947 sensu lato currently consists of five nominal species distributed in Africa and Asia (World Spider Catalog 2026). It was established for C. kittenbergeri Caporiacco, 1947, with a superficial generic diagnosis relying only on somatic features such as length of eye rows, leg spination and relative leg lengths (Caporiacco 1947). Roewer (1955), following Caporiacco’s (1947) generic diagnosis, drastically increased the number of Crocodilosa species by transferring several species from other lycosid genera, but most of these subsequently added species were later reassigned to their appropriate genera (World Spider Catalog 2026), highlighting the need for a re-examination of the type species and remaining congeners to clarify the validity of Crocodilosa. At present, the genus ha...

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

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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 showed that bite force scaled isometrically with head dimensions but showed negative allometry relative to body length, reflecting ontogenetic body elongation rather than diminished cranial performance. When expressed as pressure, biting by Drymarchon generated tissue-level stresses exceeding those produced by constriction in comparably sized snakes. Dietary synthesis revealed extreme trophic breadth dominated by non-avian reptiles, particularly snakes, with no relationship between predator size and prey size. Together, these results resolve a biomechanical paradox by demonstrating that high bite pressure, prolonged jaw engagement, and behavioral persistence can support lethal prey subjugation in the absence of venom or constriction. These findings highlight simple seizing as an effective and underappreciated prey-handling strategy, and underscore the importance of integrating biomechanics, behavior, and natural history to understand the evolution of snake feeding systems.
Evenson, J., & Penning, D. (2026). Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon. Zoology, 126348. https://doi.org/10.1016/j.zool.2026.126348