Dipsas oneilli (ROSSMAN & THOMAS, 1979)
Can you confirm these amateur observations of Dipsas oneilli?
Dipsas oneilli
We have no photos, try to find some by Google images search: 
| Higher Taxa | Colubridae (Dipsadinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes) |
| Subspecies | |
| Common Names | E: O'Neill's Tree Snake |
| Synonym | Sibynomorphus oneilli ROSSMAN & THOMAS 1979 Sibynomorphus oneilli — CADLE 2007 Sibynomorphus oneilli — WALLACH et al. 2014: 670 Dipsas oneilli — ARTEAGA et al. 2018 |
| Distribution | Peru (from the northern end of the Cordillera Oriental in extreme southern Amazonas Department, Peru, and in the Cordillera Occidental from southern Ancash to southern Cajamarca Department), elevation 1646-3500 m. Type locality: ‘‘NNE Balsas on the road to Abra Chanchillo, Departamento de Amazonas, Peru (ca. 1645 m [elevation]).’’ |
| Reproduction | oviparous |
| Types | Holotype: LSUM 33736, male |
| Diagnosis | Diagnosis: Sibynomorphus oneilli has a large number (38–63) of dark crossbands on the dorsum throughout the length of the body when discrete crossbands are present (the most common condition) (Fig. 9). In some specimens, the dorsal crossbands are complete only anteriorly; the posterior crossbands in these specimens are incomplete middorsally and appear as narrow lateral bars. Several specimens from the R ́ıo Santa valley lack discrete bands entirely; instead, the dorsum has an obscure network of dark flecks or reticulations. The anterior crossbands (generally two to three dorsal rows wide) are slightly broader than, or equal in width to, the interspaces, whereas most crossbands are only one dorsal row wide and much narrower than the interspaces. The venter is heavily checkered or spotted with large bold markings (rounded, squarish, or half-moon–shaped) (Fig. 9). Ventrals are 152–168 in males; 163–173 in females. Subcaudals are 62–77 in males; 56–64 in females. Infralabials are 9–13. Sibynomorphus oneilli differs from other species of Sibynomorphus in Ecuador and Peru as follows. In S. oligozonatus, S. vagrans, and S. williamsi, the anterior crossbands are usually twice or more as broad as the interspaces (see illustrations in the species accounts), whereas in S. oneilli, crossbands are usually equivalent to, or narrower than, the interspaces (occasionally broader than interspaces but never approaching twice their width). These species also differ from S. oneilli in other characters: S. oligozonatus has fewer supralabials (6–7) and a less boldly patterned venter (Figs. 1, 2, 4, 6). Sibynomorphus williamsi has fewer supralabials (6–7) and a greater number of ventrals (males, 173–182; females, 181–188) than S. oneilli. Sibynomorphus oneilli averages about 10 more ventrals and 15 fewer subcaudals than S. vagrans when sexes are considered separately (Table 1). Sibynomorphus vagus differs from S. oneilli in temporal scale patterns (Table 1) and by having fewer ventrals (males, 144– 152; females, 151–158). Sibynomorphus petersi has a greater number of ventrals (164–188, sexes combined) and subcaudals (males, 75–87; females, 65–77) than S. oneilli and has different color patterns on the head and body. (Cadle 2007) Unfortunately we had to temporarily remove additional information as this was scraped by multiple AI companies who sell that data to their customers. These details, e.g. detailed descriptions or comparisons (about 8088 characters) are available for collaborators and contributors. Please contact us for details. |
| Comment | Abundance: Sibynomorphus oneilli has been reported in the literature from only two males (including the juvenile male holotype) and a female (Rossman and Kizirian, 1993). Cadle (2007) refers an additional 14 specimens to this species. Diet: primarily molluscs (T. de Lema, pers. comm., 16 Oct 2015). Habitat: fully arboreal (Harrington et al. 2018). Distribution: see map in Cadle 2007: 253 (Fig. 43). |
| Etymology | Named after John P. O'Neill (b. 1942), an American field ornithologist and artist. |
| References |
|
| External links |