Ophryacus smaragdinus GRÜNWALD, JONES, FRANZ-CHÁVEZ & AHUMADA-CARiLLO, 2015
Can you confirm these amateur observations of Ophryacus smaragdinus?
|Higher Taxa||Viperidae, Crotalinae, Colubroidea, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||Emerald Horned Pitviper|
|Synonym||Ophryacus smaragdinus GRÜNWALD, JONES, FRANZ-CHÁVEZ & AHUMADA-CARILLO 2015|
Ophryacus undulatus — FLORES-VILLELA et al. 1992: 249.
Ophryacus undulatus — CAMARILLO 1995: 196.
Ophryacus undulatus — CAMPBELL & LAMAR 2004: 454 (in part).
Ophryacus undulatus — MENDOZA-PAZ et al. 2006: 109 (in part).
Ophryacus undulatus — RAMÍREZ-BAUTISTA et al. 2010: 77
Ophryacus undulatus — SOLANO-ZAVALETA et al. 2010: 381
Ophryacus undulatus — RAMÍREZ-BAUTISTA et al. 2014: 177
|Distribution||Mexico (Veracruz, Hidalgo, Puebla, Oaxaca), elevation 1,400 - 2,400 m |
Type locality: Los Ocotes (20.601542, -98.469708; datum WGS 84; elev. 2,150 m asl), Zilacatipan, Municipio de Huayacocotola, Veracruz, Sierra Madre Oriental, Mexico
|Types||Holotype: MZFC 29290, adult female, collected by Jason M. Jones and Iván T. Ahumada-Carrillo on 2 November 2013.|
Paratypes: Seven specimens. MEXICO: HIDALGO: El Potrero, Municipio de Tenango de Doria (20.314922, -98.229653; datum WGS 84; elev. 2,200 m), an adult male collected 25 August 1990 by students of the Escuela Nacional Estatal y Profesional de Iztacala, UNAM (MZFC 21140); “Doria,” Municipio de Tengano de Doria (20.314922, -98.229653; datum WGS 84; elev. 2,200 m), an adult male collected on 14 July 1990 by Efraín Hernández-García (MZFC 04825). OAXACA: San Martín Caballero, Municipio de San José Tenango (18.108175, -96.633981; datum WGS 84; elev. 1,360 m), an adult male collected 25 May 1994 by Mario Mancilla-Moreno (MZFC 13556); San Martín Caballero, Municipio de San José Tenango (18.108175, -96.633981; datum WGS 84; elev. 1,360 m), a juvenile female collected 28 May 1994, collector unknown (MZFC 13557). PUEBLA: Xucayucan, Municipio de Tlatlauquitepec (19.895744, -97.471700; datum WGS 84; elev. 1,630 m), a juvenile female collected 27 May 2005 by Israel Solano-Zavaleta (MZFC 17663). VERACRUZ: Cerro La Campana, Ticuautipan, Municipio de Xico (19.439500, -97.078078; datum WGS 84; elev. 2,045 m), a subadult female collected on 26 October 2003 by Itzel Durán Fuentes (MZFC 20582); and Zilacatipan, Municipio de Huayacocotla (20.655761, -98.424894; datum WGS 84; elev. 1,790 m), a subadult female, collected on 2 November 2013 by Jason M. Jones and Iván T. Ahumada-Carrillo (MZFC 29289).
|Diagnosis||Diagnosis: Ophryacus smaragdinus can be distinguished from all other pitvipers in North America by the combination of the following characters: absence of a rattle; divided subcaudal scales; presence of a supraocular horn that is not in immediate contact with the eye; fewer than 30 interrictal scales; and usually fewer than 10 supralabials on each side of the head (Fig. 2). A distinctive white, cream, or pale yellow triangular marking is present on the lateral surfaces of the head, starting just below the suboculars and extending diagonally onto the 5th and 6th supralabials; this pale marking often extends onto the 7th and 8th (if present) supralabials. Secondary pale markings also are present on the 1st and 3rd supralabials, whereas the color of the 2nd and 4th supralabials is the same as the ground color of the head. This pale-colored triangular marking and the associated secondary pale markings are diagnostic for this species, and when viewing photographic material are helpful in distinguishing it from its congeners (Fig. 9A, B, C in Grünwald et al. 2015).|
Comparisons: Ophryacus smaragdinus is morphologically similar to O. undulatus and species of the genus Mixcoatlus, including M. melanurus, M. browni, and, to a lesser degree, M. barbouri. Ophryacus smaragdinus can be distinguished from O. undulatus by the presence of a supraocular horn that is separated from the eye by one or two rows of small supraocular scales (Figs. 2A, 9A, B, C), as well as by the presence of fewer supralabials (often seven or eight on at least one side, but no more than 10), whereas in O. undulatus usually 11 or more are present on each side, but no fewer than nine. In O. smaragdinus 1–4 postrostral internasals are present, followed by a row of 5–7 anterior intercanthals, all of which are small and distinctly keeled. In contrast, 2–3 postrostral internasals are present in O. undulatus, which lack a keel and are followed by a row of 5–7 anterior intercanthals, of which the outer ones are large and flat and the smaller inner scales are slightly keeled. In O. smaragdinus 22–29 interrictals are present, whereas in O. undulatus there are 31–36. The upper preocular in O. smaragdinus is shorter than in O. undulatus, with a length of 25–50% of the eye diameter, compared to 70% or more in the latter species (Figs. 9, 10). The condition of the canthals also differs in the two species; whereas they might be prominent in both, the canthals of O. smaragdinus are rounded and slightly elevated, but those in O. undulatus are pointed and raised into horns (Figs. 9, 10). Finally, although the coloration of both species is variable, individuals of O. smaragdinus can be distinguished from those of O. undulatus by the presence of a white, cream, or pale yellow triangular marking that extends from the posterior portion of the eye diagonally onto the 5th and 6th supralabials. This triangular marking is not present in O. undulatus (Figs. 4, 9). See Table 1 here and below for a comparison of the distinctive characters among the various species.
Ophryacus smaragdinus can be distinguished from O. undulatus from the Pacific versant of the Sierra Madre del Sur, Oaxaca (Ophryacus sphenophrys new comb.; see below) by the presence of a supraocular horn that is not in immediate contact with the eye, and which is taller than wide (Fig. 2). In O. undulatus from the Pacific versant of the Sierra Madre del Sur, Oaxaca, the horn is wider than tall and in contact with the eye (Figs. 6A; 10C, D). Furthermore, four characters also are useful in distinguishing the two species. Values for O. undulatus from the Pacific versant of the Sierra Madre del Sur, Oaxaca follow those for O. smaragdinus: a shorter tail in males (less than 15% of SVL, compared to over 17%), fewer supralabials (usually 7–9, vs. 10), fewer interrictals (22–29, as opposed to 33), and fewer subcaudals (39–46, as opposed to 51–57).
Ophryacus smaragdinus can be distinguished from M. melanurus by the presence of divided subcaudals, a supraocular horn that is separated from the eye by one or two rows of small supraoculars, and fewer supralabials (7–9 vs. 10–14 in M. melanurus). Furthermore, M. melanurus is gray and not green, whereas O. smaragdinus is green or brown and not gray (Fig. 4). Ophryacus smaragdinus can be distinguished from the other two species of Mixcoatlus by the presence of supraocular horns, as well as by the number of intersupraoculars (11 in O. smaragdinus vs. 1 in M. browni and 3–4 in M. barbouri (Figs. 9, 10). Additionally, in O. smaragdinus one or two scales are present between the subocular and the supralabials, whereas in M. browni and M. barbouri the suboculars are in contact with the supralabials (Figs. 9, 10).
|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.|