Tantilla excelsa, McCranie & Smith, 2017

McCranie, James R. & Smith, Eric N., 2017, A Review of the Tantilla taeniata Species Group (Reptilia: Squamata: Colubridae: Colubrinae) in Honduras, with the Description of Three New Species, Herpetologica 73 (4), pp. 338-348 : 342-344

Tantilla excelsa sp. nov.

( Figs. 6 , 7 )

Tantilla taeniata: Wilson and Meyer 1971:32 , in part; Wilson 1982:56, in part; Wilson and Meyer 1982:109, in part; Wilson and Meyer 1985:103, in part; Wilson and McCranie 1999:328, in part; McCranie 2011a:227, in part; McCranie 2011b:44, in part; McCranie et al. 2012:623; Wilson and Mata-Silva 2015:457, in part.

Holotype. — USNM 579682 , an adult male from Lancetilla (15°44 ′ N, 87°27 ′ W), 30 m elevation, department of Atlántida, Honduras, collected 26 February 2011 by Leonel Marineros.

Paratypes (n ¼ 3). — UF 157566 , an adult female from Compañia Agricola Paradise near Peña Blanca (14°58 ′ N, 88°01 ′ W), 700 m elevation, Cortés, Honduras ; UMMZ 58417 , an adult female that is dehydrated and has an incomplete tail, from El Progreso (15°24 ′ N, 87°48 ′ W), Yoro, Honduras , 30 m elevation; MCZ 22045 , head and anterior portion of body of an adult, from Progreso District , Yoro, Honduras , about 30 m elevation.

Diagnosis. — Tantilla excelsa (in preservative) is defined by the following combination of characters: (1) pale middorsal stripe tan, extending length of body and at least half of tail, stripe on vertebral row and adjacent halves of paravertebral rows throughout its length; (2) tan to white lateral stripe occupying adjacent halves of scale rows 3 and 4; (3) ventrolateral area similar in pale color to that of lateral stripe; (4) lower two-thirds anteriorly and about lower third posteriorly of scale row 1 white similar to that of ventrals; (5) lateral edges of ventrals white, no, or very few, dark spots present; (6) ventral and subcaudal surfaces yellow (shortly after death) and white; (7) two females with 161–178 ventrals, single male with 169 ventrals, subcaudals 61 in one female, 70 in male; (8) tail length 23% of total length in one female, 24% in male.

Tantilla excelsa can be distinguished from T. taeniata by having 169 ventrals in single male, 161–178 in two females, and by having yellow ventral surfaces in life (vs. 141–152 ventrals in males and 150 in single known female, and ventral surfaces pale purplish pink grading to darker salmon color on posterior two-thirds of body and tail).

Tantilla excelsa differs from T. impensa and T. stenigrammi by having the middorsal pale stripe involving all of the vertebral scale row and adjacent thirds of paravertebral scale rows throughout its length (vs. middorsal stripe confined to vertebral row in those two species [on at least anterior half of body in T. stenigrammi ]) and having female ventrals numbering up to 178 (vs. to 172 in T. impensa and 159 in female T. stenigrammi ). Tantilla excelsa differs from T. olŋmpia in having complete middorsal and lateral pale stripes, with the middorsal stripe extending onto lateral edges of paravertebral rows, and having 169 ventrals and 70 subcaudal scales in single male (vs. those stripes reduced to dashes and spots, respectively; pale middorsal dashes restricted to vertebral row; and 148 ventrals and 49 subcaudals in a male specimen). Tantilla excelsa differs from T. psittaca by having yellow ventral and subcaudal surfaces in life and white to pale yellow in preservative and in having 169 ventrals in single male and 161–178 in two females (vs. those surfaces pink and grading to red in life and pale brown medially and pale brown with pinkish tinge on posterior third of body and under tail in preservative, 153–163 ventrals in males and 154–161 in female specimens). Tantilla excelsa differs from T. tritaeniata in having 169 ventrals in single male and 161–178 ventrals in two females, and having a complete pale nuchal collar (vs. 157 ventrals in single male and 155–161 in females, and pale nuchal collar divided).

Description of holotype. —An adult male; TOL 400 mm; SVL 305 mm; TAL 95 mm (23.8% of TOL); HL 9.8 mm; HW 5.5 mm (level of angle of mouth); head barely distinct from neck; snout broadly rounded in dorsal view; eye length 1.3 mm; snout length 3.0 mm, about 2.3 times longer than eye; pupil circular; rostral about 1.1 times wider than high (2.2 X 2.0 mm); internasal length about 0.8 times width (1.1 X 1.4 mm); prefrontal larger than internasal, wider than long (2.2 X 1.5 mm); median prefrontal suture 1.4 mm, about half as long as frontal; frontal with slight anterior extension, Vshaped posteriorly, about 1.0 times longer than wide (2.9 X 2.8 mm), about 1.0 times longer than distance from its anterior edge to tip of snout (2.9 X 2.8 mm); parietal about 1.5 times longer than wide (4.1 X 2.8 mm), median parietal suture length 3.0 mm, about 1.0 times longer than length of frontal (2.9 mm); parietals contacting five nuchal scales; supraocular about 1.6 times longer than wide (2.3 X 1.4 mm), bordering orbit, contacting parietal, upper postocular, preocular, frontal, and prefrontal.

Nasal divided, anterior nasal contacting rostral, internasal, and supralabial 1, posterior nasal contacting internasal, prefrontal, preocular, and supralabials 1 and 2, nostril located in central portion of nasal (forming division of nasal); loreal absent; preocular single, about 1.4 times higher than long (0.7 m X 0.5 mm), lower edge contacting supralabials 2 and 3; postoculars 2, upper about 1.5 times larger than lower (upper height 0.6 mm, lower height 0.4 mm); temporals 1 þ 1, anterior temporal 1.5 times longer than high (1.9 X 1.3 mm), posterior temporal 1.8 times longer than high (1.6 X 0.9 mm); supralabials 7, 3 and 4 bordering orbit, 4 and 5 contacting lower postocular, 5 also contacting anterior temporal, 6 contacting anterior temporal, 7 contacting anterior and posterior temporals; infralabials 6– 7, first 2 contacting anterior pair of chinshields on side with 6 infralabials (left side), first 3 contacting anterior pair of chinshields on side with 7 infralabials (right side); infralabial 1 on each side separated medially by contact with anterior chinshield; mental about 1.6 times wider than long (1.4 X 0.9 mm), contacting first pair of infralabials and anterior pair of chinshields; anterior chinshields about 2.4 times longer than wide (2.6 X 1.1 mm), not extending laterally to border of lip; posterior pair of chinshields about 1.7 times longer than wide (1.7 X 1.0 mm), posterior tips separated from each other by two rows of gular scales; four preventral scales between gular 1 and ventral 1; dorsal scales in 15–15–15 transverse rows, smooth throughout, lacking apical pits and supracloacal tubercles; dorsal scales in six rows at level of subcaudal 10; ventrals 169; cloacal scute divided; subcaudals 70, paired; ventrals plus subcaudals 239.

Color of holotype in life. —Other than noting the ventral and subcaudal surfaces were yellow (L. Marineros, personal communication), the collector of the holotype did not record color notes of the recently killed specimen.

Color of holotype in preservative ( Figs. 6 , 7 ). —Dorsal surfaces brown with white nuchal collar, tan middorsal stripe, and white lateral stripe; tan middorsal stripe includes vertebral row and adjacent tips to a third of paravertebral scale rows; tan middorsal stripe narrowing anteriorly on first scale involved in stripe, extending onto tail, fading out at about midlength of tail; tan middorsal stripe beginning on scale 4 posterior to parietals; broader white lateral stripe present, covering adjacent halves of scale rows 3 and 4, bordered above by continuous, thin dark brown line; white lateral stripe beginning on scale 5 posterior to supralabial 7, extending well onto tail to nearly reaching tip; lower twothirds of scale row 1 white anteriorly, grading to white only reaching lower tips of scale row 1 posteriorly on body; about upper third of scale row 1, all of scale row 2, and lower third of scale row 3 same shade of brown as paravertebral rows on about anterior half of body, before reducing width posteriorly; pale nuchal collar complete, not involving posterior tips of parietals, but involving first two scale rows dorsally, pale nuchal collar also involving posterior half of ultimate supralabial plus two scale rows laterally; dorsal surface of head brown, other than dark brown line crossing posterior tips of parietals to connect with lateral dark head bar; white, with dirty white flecking lateral spot involving postnasal, supralabial 1, and anterior half of supralabial 2; larger white spot posterior to eye involving anterior half of anterior temporal, all of supralabial 5, and tips of supralabials 4 and 6; dark brown lateral bar involving posterior half of supralabial 7, adjacent two-thirds of supralabial 6, and all of posterior temporal to connect with dark brown parietal cross-line; lateral dark bar narrowing only slightly dorsally; anterior tip of mental scale and lateral tips of infralabials 1 and 2 with brown flecking; dark brown spot present on infralabial 4 and adjacent edge of infralabial 5, remainder of ventral surface of head white; ventral surfaces of body and tail white for full length, except for variation discussed above.

Variation in paratypes. —Two adult female paratypes show the following variation (followed by mean in parentheses): TOL 326 mm in one ( UF 157566 ; UMMZ 58417 has incomplete tail); SVL 251–276 (263.5). mm; TAL 23.0% of TOL in one; ventrals 161–178 (169.5); subcaudals 61 in one; ventrals plus subcaudals 222 in one. All paratypes (including MCZ R22045 , a head and anterior portion of body only of an adult) have 7 supralabials on each side, with supralabials 3 and 4 bordering the eye. Available color pattern notes indicate those paratypes were similar overall to the color pattern of the holotype.

Distribution and habitat. —Very little is known about the habitats of Tantilla excelsa . The holotype was killed by a worker at the Lancetilla Botanical Gardens during February. The UF specimen was taken after dark as it was crawling on the ground on a coffee farm during May. The UMMZ specimen was collected on 27 March 1923 and possibly came from an insect trap (G. Schneider, personal communication). No data are available for the MCZ paratype other than it was collected in 1925. The Lancetilla Botanical Gardens formerly contained Lowland Moist Forest and lies at 30 m elevation. The coffee farm is in an area formerly containing Premontane Wet Forest and lies at 700 m elevation. The remaining two localities are in Lowland Dry Forest, although more mesic corridors of gallery forest do occur in those areas. Thus, T. excelsa is known to occur at low and moderate elevations (30–700 m) on both sides of the Río Ulúa drainage, and from the vicinity of Lago de Yojoa, Cortés, to the north-northeast in the vicinity of Lancetilla, Atlántida ( Fig. 5 ).

Etymology. —The specific name excelsa is an adjective from the Latin excelsus, which in this case means high. The name refers to the relatively high number of ventral scales in this nominal form.

Figures

FIG. 6.—Tantilla excelsa holotype (USNM 579682), an adult male. Total length of head, body, and tail ¼ 400 mm. Image taken by JRM (UTADC 8865). A color version of this figure is available online.

FIG. 7.—Lateral view of the head and body of the Tantilla excelsa holotype (USNM 579682). Head length ¼ 9.8 mm. Image taken by JRM (UTADC 8866). A color version of this figure is available online.

FIG. 5.—Map showing localities for the species of the Tantilla taeniata group known to occur in Honduras, including three new species (T. excelsa, T. gottei, and T. stenigrammi). Type localities are indicated by filled symbols. Known localities in adjacent Guatemala are shown for T. impensa.