Tuesday, January 12, 2016

[Herpetology • 2015] Ophryacus smaragdinus • A New Species of Ophryacus (Viperidae: Crotalinae) from eastern Mexico, with comments on the Taxonomy of related Pitvipers

Emerald Horned Pitviper | Ophryacus smaragdinus 
Grünwald, Jones, Franz-Chávez & Ahumada-Carrillo, 2015

Endemic to Mexico, snakes of the genera Ophryacus and Mixcoatlus are some of the most unusual pitvipers in the country. The taxonomy and natural history of members of these genera has not been studied extensively, perhaps because individuals are difficult to encounter in the field and thus rarely are deposited in museum collections. A specimen collected in 2010 in western Veracruz did not match any of the known species in these genera, resulting in a two-year study. Pictured here is a new species of Ophryacus from Zilacatipan, Municipio de Huayacocotla, Veracruz, Mexico.
photo: Iván Ahumada-Carrillo

The genus Ophryacus is endemic to Mexico, where it ranges along the Sierra Madre Oriental from Hidalgo and northern Veracuz south to the Sierra Madre del Sur in Guerrero and Oaxaca. We obtained new material of Ophryacus and compared it to specimens from all previously documented populations of O. undulatus. We examined scutellational characters and proportional differences, and found strong evidence to support the existence of at least three species within this genus. One species is undescribed and another currently is in the synonymy of O. undulatus. We describe a new species of Ophryacus from eastern Mexico, and remove Bothrops sphenophrys from the synonymy of O. undulatus and formally place it in Ophryacus. We provide comparative morphological data and a key for the known species of Ophryacus and Mixcoatlus. We also discuss the ecological and geographical distribution of Ophryacus and Mixcoatlus and include a distribution map for all the species with supraocular horns. Finally, we comment on the conservation implications for the horned pitvipers of Mexico.

Key Words: Biogeography, conservation implications, external morphology, Hidalgo, Mixcoatlus, Oaxaca, Puebla, Sierra Madre del Sur, Sierra Madre Oriental, taxonomy, Veracruz

Fig. 14. An adult Ophryacus sphenophrys collected near the type locality of La Soledad, Municipio de Candelaria Loxicha, Oaxaca. This paper was “in press” at the time of capture (16 December 2015), so coloration and meristic data for this individual does not appear in the text.
photo: Christoph I. Grünwald

Distribution and Natural History: Ophryacus smaragdinus apparently is restricted to montane cloud forest, humid pine-oak woodland, and pine forest (Fig. 12A), but also has been found in disturbed areas with secondary vegetation. Although this species appears to be less arboreal than what has been reported for O. undulatus in Guerrero and Oaxaca (Campbell and Lamar, 2004: 452), it has been collected at a height of up to 1 m in low bushes (Flores-Villela et al., 1992). Other individuals have been found under fallen logs, in woodpiles, and on the ground in vegetation. Whereas most individuals have been encountered during the day, one individual from Veracruz (UAZ- 57622-PSV) was found crossing a road at 2258 h during foggy weather.

Ophryacus smaragdinus has been collected in east-central Hidalgo, west-central Veracruz, northeastern Puebla, and north-central Oaxaca, where it ranges along the humid eastern slopes of the Sierra Madre Oriental from at least as far north as Zilacatipan, in the municipality of Huayacocotla, Veracruz, south to at least San Martín Caballero, in the municipality of San José Tenango, Oaxaca. Its elevational distribution ranges from about 1,400 m in Oaxaca to at least 2,340 m in Hidalgo and Veracruz (see Fig. 11).

Etymology: The specific epithet is derived from the Latin word smaragdinus, an adjective meaning “emerald-green,” in reference to the emerald green ground coloration exhibited by most individuals of this species.

Christoph I. Grünwald, Jason M. Jones, Hector Franz-Chávez and Iván T. Ahumada-Carrillo. 2015. A New Species of Ophryacus (Serpentes: Viperidae: Crotalinae) from eastern Mexico, with comments on the Taxonomy of related Pitvipers. Mesoamerican Herpetology. 2(4); 388–416.

New species of venomous snake discovered in endangered Mexican cloud forests http://news.mongabay.com/2016/01/new-species-of-pitvipers-discovered-in-endangered-mexican-cloud-forests/

Resumen: El género Ophryacus es endémico a México con una distribución que abarca desde la Sierra Madre Oriental en Hidalgo y el norte de Veracruz hasta la Sierra Madre del Sur en Guerrero y Oaxaca. Se obtuvó nuevo material de Ophryacus y se comparó con espécimenes de todas las poblaciones previamente documentadas. Examinamos caracteres de escamación y diferencias proporcionales, y encontramos evidencia singificativa que confirman la existencia de al menos tres especies en este género. Una especie no está descrita y la otra actualmente esta sinonimizada con O. undulatus. Describimos una especie nueva de Ophryacus del este de México y removemos Bothrops sphenophrys de la sinonimia de O. undulatus y la colocamos formalmente en Ophryacus. Proporcionamos datos morfológicos comparativos y la claves para las especies conocidas de Ophryacus y Mixcoatlus. También discutimos la distribución geográfica y ecológica de Ophryacus y Mixcoatlus e incluimos un mapa de distribución para todas las especies con cuernos supraoculares. Finalmente comentamos sobre las implicaciones de conservación para todas las víboras de foseta cornudas de México.

Palabras Claves: Biogeografía, Hidalgo, implicaciones de conservación, Mixcoatlus, morfología externa, Oaxaca, Puebla, Sierra Madre del Sur, Sierra Madre Oriental, taxonomía, Veracruz