Oxybelis acuminatus (Wied, 1824)

Jadin, Robert C., Jowers, Michael J., Orlofske, Sarah A., Duellman, William E., Christopher Blair, & Murphy, John C., 2021, A new vine snake (Reptilia, Colubridae, Oxybelis) from Peru and redescription of O. acuminatus, Evolutionary Systematics 5 (1), pp. 1-12 : 1

Oxybelis acuminatus (Wied, 1824)

Coluber acuminatus - Wied, in Anonymous, 1824: 667. Holotype AMNH 3886. The type locality Rio Espirito Santo, in southeastern Brazil (~ 19°2'S, 40°43'W). Note that the name Coluber acuminatus was published in June of 1824, and it was long given priority over Wagler’s Dryinus aeneus 1824, which was published in March of 1824, see Keiser (1974:4).

Oxybelis aeneus aeneus - Bogert & Oliver, 1945: 391. Bogert and Oliver (1945) reported on the type specimen, a female that is 1255 mm in total length with a 444 mm incomplete tail; the dorsal scales are in 17-17-15 rows; it has 197 ventral scales and 144 subcaudal scales but the tail tip is missing; the upper labials are 8/9, the fourth and fifth border the orbit on the right side, and upper labials 4-5-6 border the orbit on the left side; lower labials are 8/8; the preocular is single on both sides and two postoculars occur on each side; head width is 9.4 mm and the length is 23.8 (hl/w ratio is 2.53); eye diameter is 4.4 mm and the internasal is 4.6 mm (0.95 eye diameter/internasal ratio).

Diagnosis.

A vine snake with (1) three upper labials (4-5-6) bordering the orbit on the left; (2) black bars or spots present on the anterior body; (3) indistinct stripe on the outer edges of ventral scales, venter finely mottled; (4) eye diameter greater than preocular length; (5) second pair of chin shields separated by smaller scales for most of their length; (6) nine upper labials, three located behind the orbit; (7) snout from above relatively broad, slightly tapered, and flat at rostrum; (8) supraocular longer than prefrontals; (9) last upper labial longer than primary temporal; (10) lower surface of head uniform in color; (11) second upper labial in contact with preocular (this character state appears to occurs only in this taxa).

Comparison.

Oxybelis acuminatus can be distinguished from all other members in the O. aeneus complex by having their second upper labial contacting their preocular (Fig. 2B ); all other species have the third upper labial contacting the preocular (Table 1 ). Five lower labials are contacting the chin shields, a character state occasionally seen in O. rutherfordi from northern South America and O. vittatus from Panama. Posteriorly the lower dorsum and ventral surface of the body and the tail have scattered small black spots. Keiser (1974) reported 17-20 maxillary teeth in specimens from southeastern Brazil. These traits and its presence in Brazil’s Atlantic Forest, a center for endemism, revalidate this species.

Distribution.

This species is likely restricted to the Atlantic Forest of southeastern Brazil.

Figures

Figure 2. A, Illustration of Coluber acuminatus reproduced from Wied 1824. B, Holotype of O. acuminatus AMNH 3886.