Opisthotropis
Creators: name: David, Patrick
name: Pham, Cuong The
name: Nguyen, Truong Quang
name: Ziegler, Thomas
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Colubridae
Opisthotropis

description: Key to the species of Opisthotropis and related genera
On the basis of recent taxonomic modifications and of new material available subsequent to Ziegler et al. (2008), we provide a new key to the genus Opisthotropis and related genera. This key, as well as Table 1 above, are based on specimens examined by us and the references listed in the Materials and Methods.
1 Posterior upper maxillary teeth distinctly enlarged; nostrils rounded, dorsolateral, laterally directed; first supralabials distinctly longer than high................................................................... Parahelicops annamensis
- Upper maxillary teeth subequal; nostrils crescentic, in dorsal position, directed upwards; first supralabials distinctly higher than long............................................................................................ 2
2 15 or 17 scale rows at midbody and on neck............................................................... 3
- 19 rows at midbody, 19–23 rows on neck.................................................................. 16
3 15 scale rows at midbody, 15–17 scale rows on neck.......................................................... 4
- 17 rows at midbody.................................................................................... 7
4 Internasal in contact with loreal................................................................... O. jacobi
- Internasal not in contact with loreal....................................................................... 5
5 1 preocular; 1 anterior temporal; dorsal scales entirely smooth.................................................. 6
- 2 preoculars; 2 anterior temporals; dorsal scales keeled posteriorly...................................... O. kikuzatoi
6 9 SL; body dark with pale crossbars.......................................................... O. guangxiensis
- 8 SL; body black with a tallow spot on each dorsal scale............................................. O. maculosa
7 Dorsal scales strongly keeled (endemic to Sumatra).................................................. O. rugosa
- Dorsal scales smooth or weakly keeled on posterior part of body................................................ 8
8 No preocular; elongate loreal entering orbit....................................................... O. latouchii
- At least 1 preocular................................................................................... 9
9 Internasal in contact with loreal......................................................................... 10
- Internasal not in contact with loreal...................................................................... 12
10 Dorsal pattern uniformly blackish-brown; dorsal scales keeled posteriorly.................................... O. atra
- Dorsal pattern uniformly greyish-brown; dorsal scales smooth................................................. 11
11 Greyish-olive above; 189–194 VEN; endemic to southern Vietnam ................................... O. daovantieni
- Greyish-brown above; 183 VEN; endemic to northern Thailand ....................................... O. spenceri
12 Dorsal scales entirely smooth; dorsum with pale crossbars............................................... O. cheni
- Dorsal scales at least keeled on posterior part of body; dorsal pattern not mainly made of crossbars.................... 13
13 2 anterior temporals........................................................................ O. tamdaoensis
- 1 anterior temporal................................................................................... 14
14 Body uniformly dark with pale-edged scales; 2 suboculars........................................... O. andersonii
- Body pattern not as such; no suboculars................................................................. 15
15 A black lateral stripe separating abruptly pale colour of venter from dark dorsum colour; 159–173 VEN; 9–11 SL; 1 preocular; dorsal scales keeled throughout body............................................................. O. lateralis
- No black lateral stripe separating pale colour of venter from dark dorsum colour; 147–155 VEN; 6–8 SL; 2 preoculars; dorsal scales smooth on anterior part of body............................................................ O. maxwelli
16 Internasal in contact with loreal......................................................................... 17
- Internasal not in contact with loreal..................................................................... 19
17 1 prefrontal................................................................... Opisthotropis cucae sp. nov.
- 2 prefrontals......................................................................................... 18
18 Dorsal scales smooth; 195 VEN; endemic to the Philippines ............................................ O. alcalai
- Dorsal scales keeled; 160–176 VEN; endemic to Borneo............................................... O. typica
19 Dorsal scales strongly keeled........................................................................... 20
- Dorsal scales smooth or only weakly keeled posteriorly...................................................... 21
20 Dorsal scales with strong, thick keels; 136–140 VEN; 8–9 SL; dorsal pattern uniform..................... O. boonsongi
- Dorsal scales with strong but narrow keels; 146–154 VEN; 13–16 SL; body with black stripes............. O. kuatunensis
21 Dorsal scales keeled on posterior part of body; 190–205 VEN; strong dorsal pattern made of broad, black, pale-centred cross- bars........................................................................................ O. balteata
- Dorsal scales entirely smooth; 145–155 VEN; subdued pattern with faint dark crossbands or dark, large blotches.......... Paratapinophis praemaxillaris
description: Published as part of David, Patrick, Pham, Cuong The, Nguyen, Truong Quang & Ziegler, Thomas, 2011, A new species of the genus Opisthotropis Günther, 1872 (Squamata: Natricidae) from the highlands of Kon Tum Province, Vietnam, pp. 43-56 in Zootaxa 2758 on pages 52-53, DOI: 10.5281/zenodo.276769