Rhadinophanes monticola MYERS & CAMPBELL, 1981
Can you confirm these amateur observations of Rhadinophanes monticola?
|Higher Taxa||Colubridae (Dipsadinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Graceful Mountain Snake|
S: Culebra Graciosa de Montaña
|Synonym||Rhadinophanes monticola MYERS & CAMPBELL 1981: 5|
Rhadinophanes monticola — LINER 1994
Rhadinophanes monticola — LINER 2007
Rhadinophanes monticola — WALLACH et al. 2014: 644
Type locality: "1 mile (1.6 km.) north of Puerto del Gallo, 17˚27'N, 100˚09'W, at an elevation of approximately 9000 feet (2750 m.) on Cerro Teótepec, State of Guerrero, Mexico."
|Types||Holotype: AMNH 116332, a 357 mm male (J.A. Campbell, 21 May 1974).|
|Diagnosis||DEFINITION AND DIAGNOSIS (genus): Small terrestrial colubrids lacking hypapophyses (haemal keel present) on posterior trunk vertebrae. Intramandibular articulation of lower jaw with broad gap between dentary and compound bones.Pupil of eye round. Hemipenis one-third bilobed each lobe separately capitate,distally calyculate, and proximally spinose, lacking a nude area in asulcate side of the spinose zone; principal spines confined to lobes,with only small,slender spinules on midsection below lobes; basal one-half of hemipenis nude; sulcus spermaticus forked about halfway along organ,with centripetal branches extending to tips of lobes. High number (about 19-20+2) of maxillary teeth, the two enlarged fangs ungrooved, with knifelike posterior edges, and with the ultimate fang offset slightly laterad. Ventrolateral edge of belly nonangular. Dorsal scales smooth (except for anal ridges on at least some males), with paired apical pits, in 19-19-17 rows, the posterior reduction involving lateral rows; normal complement of colubrid head plates; anal plate divided, subcaudals paired. Color pattern basically striped albeit appearing somewhat mottled (but not crossbanded or blotched), with pale nuchal spot(s). The above combination of traits is unique. Rhadinophanes is most likely to be confused with Rhadinaea or Coniophanes, from which it differs significantly in having a centripetal sulcus spermaticus on a distinctly bilobed hemipenis that is separately calyculate and capitate on each lobe. The hemipenes of Rhadinaea and Coniophanes have a centrolineal or rarely centrifugal sulcus and are usually single, or, if slightly bifurcated (e.g., fig. 12B), the small lobes have confluent calyces contained within a single head region. The absence of grooves on the posterior maxillary teeth and the presence of scale pits also distinguish Rhadinophanes from Coniophanes. It is further distinguished from all Rhadinaea by the combination of scale pits, 19-19-17 scale rows, and rather mottled color pattern (with most Rhadinaea being excluded by any one of these traits). Despite similar hemipenes, Rhadinophanes is unlikely to be confused with its sister group, Tantalophis, since the latter has a crossbanded color pattern, a feebly elliptical pupil, and a stockier body. Rhadinophanes is further differentiated by a spacious articulation between the dentary and compound bones, apparently allowing unusual freedom of movement to the front part of the lower jaw (Myers 1981: 2).|
|Comment||Type species: Rhadinophanes monticola MYERS & CAMPBELL 1981 is the type species of the genus Rhadinophanes MYERS & CAMPBELL 1981.|
Abundance: only known from the specimen(s) described in the original description (fide Campbell et al. 2018)
Similar species: snakes of the genera Rhadinaea and Coniophanes; however, the color pattern of Rhadinophanes monticola is sufficiently distinctive that it could not be associated with Rhadinaea. Rhadinophanes lacks the grooved fangs that characterize Coniophanes. Also, the hemipenial evidence provides argument for separate generic status.
|Etymology||The species name, ‘monticola’, is Latin for ‘inhabitant of the mountains’ (Latin “colere” = inhabiting).|
The genus is named after the Greek rhadinos = slender, graceful + the suffix phanes = appearing), alluding both to the slenderness of the type species and to its superficial similarity to Rhadinaea and Coniophanes. Gender masculine.