A further new species for the genus Ananteris Thorell, 1891 (Scorpiones: Ananteridae) from a poorly prospected region of Brazilian Amazonia

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  A further new species for the genus Ananteris Thorell, 1891 (Scorpiones: Ananteridae) from a poorly prospected region of Brazilian Amazonia Abstract  A new species of the genus Ananteris Thorell, 1891 is described from the region which today defines the ‘Reserva Biológica do Río Trombetas’ in the state of Pará, Brazil. The collection of the unique specimen, presently study, took place previously to the definition of this reserve, in a joint field trip with a team of the Instituto Brasileiro de Desenvolvimento Florestal (IBDF). Ananteris antoni sp. n. is described based on one female specimen collected in a zone of dense humid forest, under death log. With this new description, the number of Ananteris species known for the scorpion fauna of Brazil is now raised to 33. Lourenço W. R., 2026. – A further new species for the genus Ananteris Thorell, 1891 (Scorpiones: Ananteridae) from a poorly prospected region of Brazilian Amazonia. Faunitaxys, 14(63): 1 – 5.  https://doi.o...

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