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...

Two new and unusual species of Tibelloides Mello-Leitão, 1939 (Araneae: Philodromidae)

 


Two new and unusual species of Tibelloides Mello-Leitão, 1939 (Araneae: Philodromidae)

Abstract

Tibelloides Mello-Leitão, 1939 currently included four species of Neotropical grass-dwelling spiders. Herein, we describe and illustrate Tibelloides castelo sp. nov. with few records from Brazil (Minas Gerais, Piauí, Rio de Janeiro), and Tibelloides juatuba sp. nov. , with records from Brazil (Minas Gerais, Pará, Paraná, Rondônia) and Paraguay (San Pedro). These two new species differ from the previously described ones by having body and legs conspicuously longer and thinner, male pedipalp without retrolateral marginal conductor, and female genitalia with compound copulatory ducts tubular and elongated.

Prado, A. W. do, Pantoja, P. & Baptista, R. L. C. (2024). Two new and unusual species of Tibelloides Mello-Leitão, 1939 (Araneae: Philodromidae). Zootaxa 5497(4): 559-576. doi:10.11646/zootaxa.5497.4.6