Not so rare snakes: a revision of the Geophis sieboldi group (Colubridae: Dipsadinae) in lower Central America and Colombia Author Savage, Jay M. Author Watling, James I. text Zoological Journal of the Linnean Society 2008 2008-07-31 153 3 561 599 https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00400.x journal article 10.1111/j.1096-3642.2008.00400.x 0024-4082 5446145 GEOPHIS ZELEDONI TAYLOR, 1954 ( FIG. 1A ) Geophis zeledoni Taylor, 1954: 693 , fig. 4 (Type locality: Costa Rica : Alajuela : Alajuela : between Volcán Barva and Volcán Poás: Finca Zeledón, c . 1829 m ; Holotype : KU31992, an adult female); Downs, 1967: 174 , fig. 19; Savage, 2002: 604 (in part); Solórzano, 2004: 292 , figs 83, 84 (in part). Diagnostics: This species is distinctive within the Geophis sieboldi species group in the following combination of features: (1) usually six supralabials, often five; (2) two supralabials lie posterior to orbit; (3) no anterior temporal or postlabials; (4) last supralabial usually separated from the parietal by a short posterior temporal; (5) usually three jubals posterior to the posterior temporal and last supralabial and the upper jubal in contact with the parietal; (6) dorsal scales in 15–15–15 rows; (7) caudal scales weakly keeled to smooth; (8) first tooth at tip of maxilla or preceded by a short toothless area; posterior half of maxilla depressed, curving ventrad posteriorly; (9) ventrals 139–143.7– 149 in males ( N = 15), 141–144.8– 150 in females ( N = 14); subcaudals 37–43.1– 46 in males ( N = 13), 36–39.3– 43 in females ( N = 12); ventrals plus subcaudals 178–184.4–191 ( N = 12); (10) dorsum and upper surface of tail uniform black; no light head band in juveniles; venter banded or variegated; subcaudals mostly to entirely black. Variation: Twelve additional specimens, five males and seven females , referable to this species bring the total to 29 known examples, 15 males and 14 females . The largest male is 379 mm in standard length, has a slightly incomplete tail but measures 417 mm overall; the largest male with a complete tail is 311 mm in standard length with a tail length of 64 mm (17.1% of total length); total length 375 mm . The largest female is 377 mm in standard length but with an incomplete tail ( 74 mm ). The largest female with a complete tail is 344 mm in standard length with a tail length of 74 mm (17.7% of total length); total length 418 mm . Relative tail lengths as percentages of total length, including data for five specimens seen by Downs (1967) , are 16.0–16.5–17.0% in juvenile males ( N = 2), 17.1–19.6–22% in adult males ( N = 5), 17.2% in a juvenile female and 16.9–18.1–21.0% in adult females ( N = 5). One juvenile female ( LACM 150741 ) has a moderately elongate posterior temporal and two jubals on the right side of the head. Examination of the maxilla confirms that this specimen is a G. zeledoni . One snake ( UCR 3953 ) has the upper jubal split into two scales on both sides of the head ( Fig. 1C ). Preoculars 0–0; postoculars 1–1 ( N = 28), 1–2 ( N = 1); the second postocular is apparently split off from supralabial 4. Supralabials 5–5 ( N = 7), 5–6 ( N = 3), 6–6 ( N = 19). The five-supralabial condition usually involves the fusion of supralabials 5 and 6; in one specimen ( LACM 150742 ) this state involves fusion of supralabials 2 and 3 on one side; supralabials 3 and 4 usually border the orbit ( N = 21); 2 and 3 border the orbit on one side ( N = 1) and 3 on both sides ( N = 7). Infralabials 4–6 ( N = 1), 5–6 ( N = 5), 6–6 ( N = 22), 6–7 ( N = 1); four infralabials are the result of fusion of 4–6 and five through fusion of 5–6; 2–4 ( N = 1), 3–3 ( N = 1), 3–4 ( N = 3) and 4–4 ( N = 24) contact the genials . Hemipenes: Based on a retracted ( Downs, 1967 ) and an everted hemipenis (UCR 3953). Organ slightly bilobed. Pedicel covered with minute spines and bearing 3–4 large spines. Truncus covered with 35–40 medium spines. Capitulum covered with spinulate calyces. Remarks: The reference by Savage (2002) to a striped specimen (UF 10438) of this species from Volcán Irazú in the Cordillera Central of Costa Rica is in error. This snake is a representative of G. brachycephalus with sloughing skin that does not show keeling on the dorsal scales. The caudal scales are strongly keeled. Examination of the maxilla confirms the re-identification. Among the snakes examined in the course of this study is a single male (USNM 297710) from Panama : Bocas del Toro-Chiriquí: Cerro Bollo: 3.5 km E Escopeta Camp. It is a male 241 mm in standard length with a tail length of 61 mm (tail length/total length, 20.2%) and 141 ventrals, 43 subcaudals for a total segmental count of 184. It agrees with other members of the group in lower Central America in having 1–1 supraoculars and 0 + 1 temporals. The first tooth on the maxilla is at the tip and the posterior portion of the bone is somewhat flattened and deflected ventrally. Other features are 6–6 supralabials (3 and 4 bordering the orbit), 0–0 preoculars, 1–1 postoculars, a short posterior temporal and 3–3 jubals in contact with the temporal and last supralabial. It is not possible to determine the number and relationship to other scales for the infralabials as this area is damaged and the condition of the snake suggests that it may have died before preservation. There are 15–15–15 dorsal scale rows with weak keels on the last 13% of the rows and on the base of the tail. The upper surfaces are uniform brownish (probably black in life), the venter is white and the subcaudals mostly white with some dark pigment on the anterior lateral margins. Surprisingly, all these features fall within the range of variation for Geophis zeledoni , a species that otherwise appears to be endemic to Volcanes Poás and Barva in the Cordillera Central or Volcanica of Costa Rica , 250 km to the north-west. Only the collection of additional material from this portion of the Serríana de Tabasará near Cerro Santiago will resolve the status of this specimen and the population that it represents. Distribution: Restricted to tropical lower montane wet forest and tropical lower montane rainforest on the slopes of Volcán Barva and Volcán Poás in the Cordillera Central of Costa Rica , 1830–2100 m ( Fig. 17 ).