Geophis lorancai, Canseco-Marquez, Luis, Pavon-Vazquez, Carlos J., Lopez-Luna, Marco Antonio & Nieto-Montes de Oca, Adrian, 2016

Canseco-Marquez, Luis, Pavon-Vazquez, Carlos J., Lopez-Luna, Marco Antonio & Nieto-Montes de Oca, Adrian, 2016, A new species of earth snake (Dipsadidae, Geophis) from Mexico, ZooKeys 610, pp. 131-145 : 133-138

Taxon classification Animalia Squamata Dipsadidae

Geophis lorancai sp. n. Figs 2, 3

Holotype

(Fig. 2). MZFC 28401, an adult male from the Instituto Tecnológico Superior de Zongolica, vicinity of Atlanca, municipality of Los Reyes, Sierra de Zongolica, Veracruz, Mexico (18°41'48"N, 97°03'21"W), 1700 m elevation, collected by Miguel Angel de la Torre Loranca on April 6, 2008.

Paratypes.

Seven specimens, six from the Sierra de Zongolica of west-central Veracruz and one from the Sierra de Quimixtlán of adjacent Puebla, Mexico. Veracruz: Three from the same locality as the holotype (MZFC 28402-03, ITSZ 217); one from Zongolica, 18°39'02"N, 97°00'29"W, 1210 m (ITSZ 071); one from 7 km E Zongolica (MZFC 28405); one from Los Reyes, 18°41'48"N, 97°03'21"W, 1700 m (ITSZ 025). Puebla: Chichiquila, 19°11'35"N, 97°03'57"W, 1700 m (MZFC 28404).

Diagnosis.

A member of the Geophis dubius group characterized by the following combination of traits: eye relatively small (see below); single supraocular and postocular present on each side; fifth supralabial and parietal in contact; mental scale and anterior chinshields in contact; smooth dorsal scales throughout the body arranged in 17 rows; ventrals 130, n = 1, in females, and 125-130, n = 7, in males; subcaudals in males 33-35, n = 5; dorsal body and tail pattern consisting of dark crossbands on a paler, red-orange background; reddish orange venter; maxillary teeth 7.

Geophis lorancai may be distinguished from all of the species in the championi and semidoliatus groups, and all of the species in the sieboldi group except Geophis dunni , Geophis nasalis , Geophis occabus , and Geophis sieboldi by having the dorsal scales arranged in 17 rows (versus dorsal scales arranged in 15 rows in the other species); and from the latter four species by having smooth dorsal scales throughout the body (versus dorsal scales keeled on at least the posterior half of the body in the other species).

Geophis lorancai differs from all of the species in the omiltemanus and chalybeus groups by having a small eye (i.e., its horizontal diameter contained nearly four times in the snout length, versus its horizontal diameter contained less than three times in the snout length in the other species); in addition, it may be distinguished from all of the species in the omiltemanus group by having the fifth supralabial and parietal in contact (versus fifth supralabial and parietal separated by one anterior temporal in the other species); from some species in the chalybeus group ( Geophis dugesii , Geophis nigrocinctus , and Geophis tarascae ) by having the dorsals arranged in 17 rows (versus dorsals arranged in 15 rows in the other species); and from the remaining species in this group ( Geophis bicolor and Geophis chalybeus ) by having the mental and anterior chinshields in contact (versus mental and anterior chinshields separated by the first pair of infralabials in the other species).

Geophis lorancai may be distinguished from the species in the latifrontalis group as follows: from Geophis blanchardi and Geophis mutitorques , by having a dorsal body pattern consisting of dark crossbands on a paler, red-orange background (versus dorsum uniformly dark in Geophis blanchardi and adults of Geophis mutitorques -juveniles with yellow collar); from Geophis latifrontalis and Geophis mutitorques , by having the fifth supralabial and parietal in contact (versus fifth supralabial and parietal separated by one anterior temporal in Geophis latifrontalis and Geophis mutitorques ); and from Geophis blanchardi and Geophis latifrontalis , by having the mental and anterior chinshields in contact (versus mental and anterior chinshields separated by the first pair of infralabials in Geophis blanchardi and Geophis latifrontalis ).

Geophis lorancai may be distinguished from the species in the dubius group as follows (Suppl. material 2: Table 2): from Geophis anocularis , Geophis carinosus , Geophis dubius , Geophis immaculatus , Geophis juarezi , Geophis rhodogaster , Geophis rostralis , and Geophis turbidus by having a dorsal body and tail pattern consisting of dark crossbands on a paler, red-orange background (versus dorsum uniformly dark in the other species, except for a pink collar present in a juvenile of Geophis turbidus ); from Geophis duellmani by having one supraocular and one postocular (versus supraocular and postocular absent in Geophis duellmani ); from Geophis fulvoguttatus by having fewer ventrals (130, n = 1, in females, and 125-130, n = 7, in males; versus 145-147, n = 2, in females, and 135-137, n = 2, in males of Geophis fulvoguttatus ); and from Geophis nephodrymus by having fewer maxillary teeth (7, n = 3; versus 11, n = 1, in Geophis nephodrymus ), a reddish orange venter (versus venter predominantly gray or yellowish cream in Geophis nephodrymus ) and more subcaudals in males (33-35, n = 5; versus 22-31, n = 6, in Geophis nephodrymus ).

Description of holotype

(Fig. 2). Adult male. Head length = 8.9 mm, snout-vent length (SVL) = 268 mm, tail length = 53.4 mm. Head slightly distinct from body. Snout long, contained 2.2 times in head, rounded from above, projecting anteriorly far beyond lower jaw; rostral 0.7 times as broad as high, portion visible from above 0.3 times as long as its distance from frontal, 1.2 times as long as internasals common suture, with posterior end approximately at level of anterior margin of nostrils; internasals broader than long (length / breadth= 0.7/0.8), slightly angulate anteriorly, in lateral contact with anterior and posterior nasals, their length and common suture 0.7/0.8 and 0.5 times as long as prefrontals common suture, respectively. Prefrontals in lateral contact with postnasal, loreal, and eye on each side, and additionally with third supralabial on left side; their length 0.6 times snout length; their common suture 0.5 times frontal length. Frontal slightly broader than long (breadth / length ratio = 1.1). Supraocular large, in contact with prefrontal, frontal, parietal, and postocular; approximately 0.9 times as long as horizontal diameter of eye, 0.6 times as long as loreal, bordering posterior half of dorsal margin of orbit, ventral margin slightly projecting posteriorly beyond posterior margin of orbit. Parietals 1.5/1.6 times as long as broad, their length 0.5 times head length, their common suture 0.8 times as long as frontal.

Nasal divided. Postnasal 1.3/1.1 times as long as prenasal. Combined length of prenasal and postnasal subequal to loreal length. Loreal 1.4/1.5 times as long as deep, contained 2.7/2.5 times in snout length, 1.6 times as long as horizontal diameter of eye, its dorsal margin slightly concave; failing to reach orbit on the left side, in broad contact with anterior margin of orbit on right side. Eye small, contained 4.3 times in snout length, its vertical diameter 0.7 times its distance from lip. One postocular, 1.4/1.3 times as high as long, 1/0.8 times as long as supraocular. Supralabials 6/6, first and second in contact with postnasal, second and third in contact with loreal, third and fourth entering orbit (third contacting prefrontal on left side), fifth largest, in contact with parietal. Ventral margin of third supralabial 1.2/1.6 times that of second supralabial; ventral margin of fifth supralabial 1.9 times that of fourth supralabial, 1.0/1.1 times that of sixth supralabial. Anterior temporal absent. One posterior temporal. Five nuchal scales in contact with parietals.

Mental 1.2 times as broad as long, pointed anteriorly, in posterior contact with anterior chinshields. Infralabials 6/6, first to third in contact with anterior chinshields, third and fourth in contact with posterior chinshields. Anterior chinshields 1.6/1.7 times as long as broad, 1.4 times as long as posterior chinshields. Posterior chinshields in narrow contact with each other anteriorly, separated posteriorly by one midgular scale. Four midgular scales. Infralabials and scales in chin region smooth. Dorsals in 17-17-17 rows, smooth throughout the body; no evident apical pits. Ventrals 128. Subcloacal scute single. Paired subcaudals 34.

Color in life (Fig. 3): Dorsal and lateral surfaces of head and anterior end of body (to approximately level of 12th middorsal scale) black; those of rest of body and tail with black transverse marks on a reddish orange background color (color 17, Spectrum orange; Smithe, 1975). Fifteen black transverse marks on body; 1 st– 2nd, 4 th– 5th, 7th, 9th, 11 th– 12th, and 14 th– 15th saddle-shaped, about 6-10 scales in length, usually extending laterally to lateral margin of ventral scales (one saddle extending laterally to third dorsal row on right side); remaining five marks consisting each of a transverse band extending on one side of body and bifurcating at midline into two transverse bands on opposite side, forming a Y-shaped mark; Y-shaped marks 7-9 scales in length at their longest. Reddish orange rings between saddles 4-6 scales in length. Eight black transverse marks on tail; anterior three saddle-shaped, about 1.5-4 scales in length, extending laterally to lateral margin of subcaudals or nearly so; 4th mark irregular, elongate, presumably formed by fusion of several adjacent transverse marks, 9.5 scales in length at its longest, in lateral contact with first dorsal scale row at three points on each side; remaining marks shorter, irregular; posterior end of tail with black and red checkered pattern. Reddish orange rings between black marks 1-2.5 scales in length. Ventral surface of head pale grey; that of body and tail immaculate reddish orange except for one dark splotch on middle of 7th ventral and black lateral ends of those ventrals involved in transverse body marks; tail surface increasingly dark posteriorly.

Dentition.

The description below is based on the dentition on the right side of paratypes ITSZ 25 and MZFC 28402 and on the left side of paratype MZFC 28403. Scored characters were consistent in all the specimens. Maxilla extending anteriorly to level of suture between 2nd and 3rd supralabials; posterior fourth of maxilla curved ventrally in lateral view; anterior tip of maxilla toothless, bluntly pointed; maxillary teeth 7, recurved; teeth slightly longer at middle of maxilla; large flange projecting medially at approximately level of middle of maxilla; posterior end of maxilla laterally compressed into moderate flange. Anterior end of ectopterygoid bifurcate; dorsal branch long, compressed; ventral branch very short, stump-like.

Variation.

This section is based on the examination of the seven paratypes. We describe only character conditions that differ from those in the holotype. Ranges are given for some characters. When ranges included the holotype, we report its condition. Two males (MZFC 28403-28404) have an incomplete tail; thus, subcaudal and total segmental counts, tail length, tail length / total length ratio, and number of tail black markings are not reported for those specimens.

Posterior temporal divided transversally on both sides in three specimens (ITSZ 71, MZFC 28402, MZFC 28405); nuchal scales in contact with parietals between posterior temporals 3-7, x = 5.7 (3, in one specimen; 5, in two; 6, in one; 7, in three with transversally divided posterior temporals). Second and third supralabials fused on both sides in ITSZ 25 (supralabials 5/5); infralabials 7/7 in one specimen (ITSZ 71). Posterior chinshields in medial contact with each other in four specimens, separated by one midgular scale in three. Midgular scales 2-3, x = 2.9 (2, in one specimen; 3, in six). Ventrals 130 in single known female; 125-130, x = 127.7, n = 7, in males, including holotype (one small scale anterior to subcloacal scute, not reaching lateral-most row of dorsals on one side, excluded from ventral counts in ITSZ 71 and MZFC 28402). Subcaudals 25 in single known female, 33-35, x = 34, n = 5, in males, including holotype; total segmental counts 155 in single known female, 159-165, x = 162.2, n = 5, in males, including holotype. Apical pits evident over vent region in two specimens (ITSZ 217, MZFC 28403).

Color pattern (Fig. 3). General pattern similar to that of holotype in all specimens. Transverse dark marks on body and tail 13-20 and 4-10, respectively. Body pattern composed of dark crossbands and Y-shaped marks in all specimens (10 and 2, in ITSZ 25; 13 and 4, in ITSZ 71; 17 and 3, in ITSZ 217; 12 and 4, in MZFC 28402; 12 and 2, in MZFC 28403; 18 and 1, in MZFC 28404; 15 and 2, in MZFC 28405) and single, unusual marks in some specimens: adjacent transverse bands connected to each other, forming a zigzagging mark, in two specimens (zigzagging mark in contact with lateral edge of ventral scales at three points on each side in ITSZ 25, at four points on one side and three points on opposite side in ITSZ 71); two adjacent transverse bands connected along midline, forming a H-shaped mark, in one specimen (MZFC 28404). Tail pattern composed of black crossbands in all specimens (7, in ITSZ 25; 8, in ITSZ 71; 2, in ITSZ 217; 7, in MZFC 28402; 5, in MZFC 28405) in addition to one Y-shaped mark in ITSZ 71, and one zigzagging mark in contact with lateral edge of ventral scales at two points on one side and three points on opposite side in ITSZ 217; posterior end of tail light in ITSZ 25, dark in MZFC 28402 and MZFC 28405, and checkered with red and black in ITSZ 71 and ITSZ 217. Ventral surface of head and body immaculate, except for black stippling, heavier on anterior portion of body, in ITSZ 71, and dark first ventral, lateral ends of ventrals gradually paler posteriorly, in two specimens (MZFC 28402-28403); ventral surface of tail paler, subcaudals adjacent to black dorsal marks with dark lateral ends; dark pigment gradually heavier pos teriorly; dark pigment on posterior edge of most subcaudals in two specimens (MZFC 28402 and 28404).

Etymology.

The specific name is treated as a noun in the genitive case and honors Biologist Miguel Ángel de la Torre Loranca, who obtained most of the specimens of the new species from the Sierra de Zongolica.

Distribution and ecology

(Fig. 1). Geophis lorancai is known from the Sierra de Zongolica of west-central Veracruz and the Sierra de Quimixtlán in adjacent extreme east-central Puebla between 1210 and 1700 m elevation (Fig. 1). All of the specimens of Geophis lorancai were obtained between October 1996 and April 2013. In these sierras, the terrain is irregular with numerous hills (some of them isolated), ascents and descents, and streams. The terrain shows a general decline towards the Gulf coastal plain (i.e., from west to east). The area is covered with cloud forest and pine-oak associations. In both sierras, Geophis lorancai is sympatric with Geophis semidoliatus , another species with dark crossbands on a red background belonging to the Geophis semidoliatus group.

All of the specimens of Geophis lorancai were found in cloud forest. The principal arboreal components of the vegetation at the type locality are Liquidambar styraciflua , Quercus spp., Saurauia scabrida , Clethra mexicana , Lippia myriocephala , Heliocarpus appendiculatus , Magnolia mexicana , Carpinus carolineana , and Ternstroemia sylvativa . The bush stratum is dominated by Psychotria galeottiana , Piper ssp., Phyllonoma laticuspis , and Miconia spp. Species found in the herbaceous stratum are Smilax spp., Selaginella spp., Begonia spp., Monstera deliciosa , Philodendron spp., Salvia spp., and Dhalia coccinea . Epiphytes of the Bromeliaceae and Orchidaceae families are common in this type of vegetation and mainly represented by the following species: Tillandsia punctulata , Tillandsia multicaulis , Nidema boothii , Lycaste deppei , and Lycaste consobrina ( Rzedowski 1978, Cázares Hernández personal communication). The specimens of Geophis lorancai were found either among the leaf litter or under fallen logs.