of patch-nosed snake (Colubridae: Salvadora Baird and Girard, 1853) from Oaxaca, Mexico Author Hernández-Jiménez, Carlos Alberto Author Flores-Villela, Oscar Author Campbell, Jonathan Atwood text Zootaxa 2019 2019-03-06 4564 2 588 600 journal article 28420 10.11646/zootaxa.4564.2.14 308d6e03-c026-4284-87e7-d30bdf6fa553 1175-5326 2589083 FF8B2AB4-51F5-46B0-AD3C-3D0C844E9FDC Salvadora gymnorhachis , sp. nov. Figs. 1, 2 urn:lsid:zoobank.org:act: FA3E5069-814D-4890-BC45-489F9AF4133B FIGURE 2. Head of holotype of Salvadora gymnorhachis sp. nov. (MZFC 28775). A, lateral view. B, dorsal view. Drawing based on a photograph taken of preserved specimen. Paratypes . Five , all from the state of Oaxaca , Mexico . A juvenile female ( AMNH 84992 ) from San Pablo Mitla , 1900 m ; an adult male ( AMNH 91090 ) from 8.3 km north of Mitla , 2100 m ; and an adult female ( AMNH 100910 ) from 2 km west of San Lorenzo Albarradas , 2000 m ; all three from Distrito de Tlacolula. An adult female ( AMNH 100909 ) from 12 km (via road) southwest of San Pedro y San Pablo Ayutla , 1760 m , Distrito de Mixe ; and an adult female ( UIMNH 56849 ), near Santa Catalina Quierí , 2364 m , Distrito de Yautepec . Diagnosis . Salvadora gymnorhachis differs from all its congeners by lacking a pale vertebral line, and dorsolateral stripes extending only to about the middle of the body (vs other species in which these stripes extend by throughout whole length of the body) ( Table 1 ); Salvadora gymnorhachis also differs from S. grahamiae , S. bairdi , S . mexicana , and S. lemniscata by having 11 maxillary teeth followed by a diastema and three enlarged teeth (9–10+ 3 in S. grahamiae and S. bairdi ; 14–15+ 3 in S . mexicana and S. lemniscata ); it further differs from S . mexicana and S. lemniscata by having fewer than 105 subcaudals (vs more than 124), a divided preocular (vs single in S. mexicana and S. lemniscata ); from S. deserticola and S. hexalepis by having second and third supralabials in contact with loreal (vs third, fourth, and sometimes fifth contacting loreal); and from S. intermedia by having six and five scale rows separating dorsolateral stripes on anterior and middle part of body, respectively (vs 3 and 1-2 scale rows separating stripes on anterior and middle part of body, respectively). TABLE 1. Comparisons of several characters among species of Salvadora . MT = Maxillary teeth, VS = ventral scales, CS = caudal scales, %TL–TaL = % of tail length in respect to total length, PS = preocular scale (Unique or Divided), TS = transversal stripes on first third of body (Absent or Present), VST = vertebral stripe along length of body, bordered by dorsolateral stripes, DS = dorsolateral stripes (Present or Absent), LS = lateral stripes (Present or Absent), PCHS = posterior pair of genials clearly separated (Present or Absent), L = loreal scale (Simple or Divided), S = supralabials, I = infralabials.

Taxon/(No.of specimens)	MT	VS	CS	%TL–TaL	PS
Salvadora bairdi (36)	9–10+3		172–205	82–105	Ĺ 28%	D
Salvadora deserticola (28)	11+3	180–201	66–86	Ĺ 28%	D
Salvadora gymnorhachis (6)	11+3	176–186	92–103	Ĺ 28%	D
Salvadora grahamiae (97)	10+3	177–202	81–107	Ĺ 28%	D
Salvadora hexalepis (88)	11–13+3		180–213	75–103	Ĺ 28%	D
Salvadora intermedia (37)	11+3	173–190	84–114	Ĺ 28%	D
Salvadora lemniscata (25)	14+3	194–205	128–141	± 29%	U
Salvadora mexicana (44)	15+3	182–197	124–145	± 29%	U
continued.
Taxon/(No.of specimens)	TS	VST	DS LS	PCHS	L	S	I
Salvadora bairdi (36)	A	P	P P	A	S	7–8	9
Salvadora deserticola (28)	A	P	P P	P	S	9–10	10–12
Salvadora gymnorhachis (6)	A	A	A A	P	S	8–9	8–10
Salvadora grahamiae (97)	A	P	P P/A	A	S	7–9	9–12
Salvadora hexalepis (88)	A	P	P P	P	D	10–12	8–11
Salvadora intermedia (37)	A	P	P P	P	S	8–10	9–12
Salvadora lemniscata (25)	A	P	P P	A	S	9–10	11–13
Salvadora mexicana (44)	P	P	P P	A	S	9	11–12

Description of holotype . Rostral with free lateral edges, extending slightly between internasal suture; plates behind rostral on top of head including prefrontals, supraoculars, frontal and paired parietals; on side of head prenasal separated from second supralabial; loreal situated above second and third supralabials; two preoculars, upper larger, contacting prefrontal and supraocular; lower preocular small, situated above third and fourth supralabials; two postoculars at left side, lower contacting fifth and sixth supralabials; one postocular at right side touching the large fifth supralabial; temporals 2 + 2, lower contacting fifth, sixth, and seventh supralabials ( Fig. 2A ); 8/8 supralabials; fourth and fifth touching eye; 8/8 infralabials, first pair meeting at midventral line behind small mental, first four pairs reaching anterior genials; fourth infralabial enlarged more than length of anterior genials; posterior genials smaller than anterior genials, separated by single row of two median scales; dorsal scales in 19 rows immediately behind head at level of ventral 3, 17 rows at level of ventral scale 13; 16 rows at midbody at level of ventral scale 90, and 13 scale rows anterior to vent at level of ventral scale 170; 182 ventrals; cloacal scute divided, bordered laterally by small scales; tail incomplete, 80+ subcaudals; 11 maxillary teeth, increasing in size posteriorly, followed by diastema and three enlarged teeth (11+3). Measurements . Total length 612 mm ; SVL 471 mm ; TaL 141 mm (tip missing), comprising about 23 % of total length. Coloration . Pattern consisting of a pair of dark dorsolateral stripes (89 Jet black; Smithe, 1975 ) beginning at level of postoculars, extending to middle of body where stripes grade into ground color; dorsolateral stripes occupying upper half of second dorsal scale row and covering four scale rows on anterior part of body, reduced to three scales wide just before becoming inconspicuous at about mid-body; field between dorsolateral stripes brown (223B Verona brown), six rows wide at anterior part of body, five at middle of body where stripes begin to fade; posterior part of body gray (45 Smoke gray); ventral surface of body whitish (92 Pale horn) except for salmon color (6 Salmon) on lateral portion of ventrals of posterior part of body and venter of tail; lateral edges of ventral scales black. Variation of Paratypes . Except for minor differences in scutelation, paratypes closely resemble holotype ( Table 2 ); ventrals in females 176–184, single male with 186 ventrals; subcaudals 92–103 in females, tail incomplete in single male; supralabials 8/ 8 in most specimens, except in female from near Municipality of San Lorenzo Albarradas , Oaxaca with 9 on one side; third and fourth supralabial reaching second (lower) postocular on individuals from District of Tlacolula , Oaxaca , whereas female from Municipality of Santa Catalina Quieri , Oaxaca ( UIMNH 56849 ) and female from Municipality of San Pedro y San Pablo Ayutla , Oaxaca (AMNH R– 100909 ) with only fifth supralabial touching postocular; anterior nasal in contact with second supralabial in all specimens, except the one from Municipality of Mitla ( AMNH 91090 ), Oaxaca, in which anterior nasal slightly separated from second supralabials; two supralabials, reaching loreal in all specimens except for one female ( AMNH 100910 ) with three on left side; body length 852 to 975 mm , male being largest in series and female holotype smallest ( Table 2 ). TABLE 2 . Variation between holotype and paratypes of Salvadora gymnorhachis in selected morphological characters. MT = maxillary teeth, VS = ventral scales, CS = caudal scales, SVL = snout vent length; TaL = tail length; S = supralabials, I = infralabials; P2S = prenasal in contact with 2nd supralabial (Contact or Separated); SCL = supralabial in contact with loreal left/right; PR = preoculars; P = postoculars; S2P = supralabials in contact with 2nd postocular; PCH = posterior pair of genials clearly separated (Present or Absent); SCE = 4th and 5th supralabials in contact with eye (Present or Absent); DSD = dorsolateral stripes disappear on the middle of the body (Present or Absent); PSF = preocular separated from frontal (Present or Absent); VST = vertebral stripe along body bordered by dorsolateral stripes (Present or Absent).

MT	VS	CS	SVL (mm)		TaL (mm)	S	I	P2S
MZFC 28775 (Holotype)	11+3	182	82+	612	141	8/8	8	S
AMNH R–84992	11+3	177	101	237	80	8/8	10	C
AMNH R–91090	11+3	186	80+	782	140	8/8	10	S
AMNH R–100910	11+3	180	103	933	218	9/8	10	C
AMNH R–100909	11+3	176	92	852	228	8/8	10	S
UIMNH –56849	11+3	184	96	8/8	C
continued.
SCL	PR	P	S2P	PCH SCE		DSD	PSF	VST
MZFC 28775 (Holotype)	2/2	2	2/1	2	P	P	P	P	A
AMNH R–84992	2/2	2	2/2	2	P	P	P	P	A
AMNH R–91090	2/2	2	2/2	2	P	P	P	P	A
AMNH R–100910	3/2	2	2/2	2	P	P	P	P	A
AMNH R–100909	2/2	2	2/2	1	P	P	P	P	A
UIMNH –56849	2/2	2	2/2	1	P	P	P	P	A

Male closely resembling females, including holotype , in lacking vertebral stripe; male paler, however, with little more than vestiges of dorsolateral stripes; prior to preservation lips and throat white, in contrast to yellow venter of anterior portion of trunk and two lowermost rows of scales (Bogert, unpublished notes); posteriorly yellow color of the venter grading into salmon color extending to underside of tail; basal portions of lower dorsal scales on the posterior of trunk appreciably darker than margins; individual having brownish body flanked with yellow anteriorly gradually becoming gray speckled with black posteriorly; dorsolateral stripes obsolescent in preserved specimen, more conspicuous in live snake. FIGURE 3. Habitat of Salvadora gymnorhachis sp. nov. A, type locality, pine-oak vegetation at 2060 m elevation. B, general view of the area at the type locality with habitat degradation (deforested areas, corn field and road), San Pedro y San Pablo Ayutla, Distrito Mixe, Oaxaca. Etymology . The specific epithet comes from the Greek “ gymnós ”, meaning “naked”, and “ ráchḭ ” dorsum, in reference that this is the only species of Salvadora that does not have dorsal vertebral stripes and has incomplete dorsolateral ones. Habitat and Conservation . The holotype was found beneath a rock in a transitional area between a crop field and pine-oak forest ( Fig. 3A ). The distribution of this species undoubtedly has been greatly modified by anthropogenic activities, which has increased the rate of deforestation at the type locality ( Fig. 3B ). None of the collection sites are located in protected areas. Despite intensive fieldwork in Oaxaca , only six specimens of this species have been collected, all between 1960 and 2014 . FIGURE 4. Geographic distribution of Salvadora gymnorhachis sp. nov. The star indicates the type locality, circles localities for paratypes. FIGURE 5. Molecular phylogenetic relationships of the genus Salvadora , based on ND4 mitochondrial gene, under the criterion of Maximun Likelihood (HKY+G model). Numbers under the nodes represent Maximum likelihood bootstrap support values. Distribution . Most individuals have been collected in central Oaxaca along the unnumbered State secondary road between Mitla and Ayutla in the Distritos de Tlacolula and Mixe at elevations of 1760 to 2364 m . The species is also known in the south near Santa Catalina Quierí in Distrito de Yautepec at elevations exceeding 1600 m . The entire range of this species is drained by the upper tributaries of the Río Tehuantepec ( Fig. 4 ). Most of the river valleys of the region contain fingers of upper tropical deciduous forest extending from lower coastal regions and the higher slopes and ridges are covered with pine-oak forest. The phylogenetic analysis performed gave one phylogenetic tree ( Fig. 5 ) with maximun likelihood value of - 2709.59. The genus Salvadora is retrieved as monophyletic, with sampled species forming two strongly supported clades ( mexicana group and grahamiae group). Salvadora gymnorachis is nested within the grahamiae group as the sister taxon of Salvadora intermedia .