New snake species discovery in Mexico

This video says about itself:

NEW SPECIES of Pitviper from Mexico

26 December 2015

HERP.MX is proud to introduce two new species of Ophryacus: the Emerald Horned Pitviper, Ophryacus smaragdinus, and the Broad-Horned Pitviper, Ophryacus sphenophrys. The description in Mesoamerican Herpetology is available here.

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The story starts in the 1850s with Swiss naturalist, Francis Sumichrast in the eastern state of Veracruz. Among Sumichrast’s important reptile and amphibian collections was a series of horned vipers which he sent to various collections around the world – including the Milan Natural History Museum in Italy. Two of these unusual vipers landed in the hands of museum director Georg Jan, who, described them as the new species Trigonocephalus (Atropos) undulatus, now Ophryacus undulatus in 1859. Typical of this era, Jan included a brief summary of the two specimens and three simple line drawings – illustrations that would prove critical when the type specimens were later destroyed during WWII.

Dozens of specimens were collected across several states in the decades that followed – including a particularly interesting snake from southern Oaxaca. During the summer of 1949, W. Leslie Burger collected a pitviper that, while superficially similar to other Ophracus undulatus, possessed distinctly wide, wedge-shaped horns, and a lower number of scales between the eyes and on the underside of the tail. Based on these differences, in 1960 Hobart Smith described Burger’s specimen as the new species: Bothrops sphenophrys and inferred a close relationship to B. undulatus (now Ophryacus).

Fast forward to 1971. Without explanation, W. Leslie Burger, the very same individual who collected the original specimen of Ophryacus sphenophrys, placed the species in synonymy with Ophryacus undulatus in his unpublished PhD dissertation at the University of Kansas. 18 years later, Campbell and Lamar followed his lead but this time noting that most of the distinguishing characters for O. sphenophrys fall within the range of known variation for O. undulatus. Unbeknownst to all parties, this “variation” was contaminated by a third, undescribed species of horned viper.

Fall of 2010 found the HERP.MX Field Team in Sierra Madre Oriental searching for the eastern limit of Crotalus aquilus in the soggy cloud forests of Veracruz. Just before 11PM on the evening of Septemer 16th, Mexican Independence Day, while returning from field work on a windy, pot-holed mountain road, a bright green pit-viper appeared in the headlights. Though similar to specimens of O. undulatus observed elsewhere, several conspicuous differences suggested the snake represented an undescribed form. Subsequent trips, specimens, and reviewing museum specimens began to shed some light on the horned viper puzzle – largely thanks to the horn itself.

Even though Jan’s original specimens had been destroyed in WWII, his drawings were precise enough to determine which snake he’d been studying half a world away, over 150 years ago. The profile view shows a narrow horn immediately above the snake’s eye, typical of Ophryacus undulatus, while these new specimens from east-central Veracruz had rounded horns separated from the eye by other smaller scales. In a stroke of good luck, a search of museum specimens revealed a second Ophryacus sphenophrys at the Universidad Nacional Autónoma de México – from the same area, and consistent with Smith’s original description. With the range of variation of O. undulatus adjusted to exclude scale counts from the new species from the north, it was apparent that Smith wasn’t off the mark after all, and Burger’s specimen from 1949 did in fact represent a distinct species.

Some time, additional specimens, scale counts, lab work, and writing later —the team is excited and proud to introduce the new species Ophryacus smaragdinus and resurrect Hobart Smith’s O. sphenophrys. Enjoy!