Micrurus nattereri Schmidt, 1952

Passos, Paulo & Fernandes, Daniel S., 2005, Variation and taxonomic status of the aquatic coral snake Micrurus surinamensis (Cuvier, 1817) (Serpentes: Elapidae), Zootaxa 953, pp. 1-14 : 10

Micrurus nattereri Schmidt, 1952 (new status)

Micrurus surinamensis nattereri Schmidt, 1952 , Fieldiana, Zoology, 34, 29

Holotype: Senckenbergische Naturforschende Gesellschaft, Frankfurt, number 20708, a female from a locality between Guaramaco and San Fernando de Atabapo in upper Orinoco River, Venezuela, collected by G. Hübner in 1895 [not examined].

Diagnosis: Distinguished from other species of the genus (except from M. surinamensis ) by frontal scale narrower than supraoculars; only one supralabial (4th) contacting the eye; head flattened with nostrils and eyes directed upwards; process pseudocoronoid extremely developed; distinguished from M. surinamensis by having 180–195 (instead of 156–174) ventrals in males and 193–215 (instead of 169–187) ventrals in females; supratemporals reaching only the posterior portion of exoccipitals rather than extending well beyond exoccipitals in M.surinamensis ; posterior portion of parietal bone blunter than in M. surinamensis which has a conspicuous sharp projection in this region.

Description and color in preservative: Scutellation and color pattern are like to Micrurus surinamensis .

Skull: General osteological features are like to Micrurus surinamensis , except that supratemporals reach only the posterior portion of exoccipitals; posterior portion of parietal bone is blunter than in M. surinamensis ; the angle formed by the point of articulation of the dentary with surangular is of approximately 20o.

Variation: Largest male 570 mm SVL, 80 mm TL; largest female 605 mm SVL, 69 mm TL; ventrals 180–195 (x = 187.3; SD = 4.65; N = 8) in males; 193–206 (x = 197.6; SD = 5.13; N = 5) in females; subcaudals 33–41 (x = 38.6; SD = 2.62; N = 8) in males; 30–38 (x = 34.0; SD = 3.8) in females; supralabials 7–8 (x = 7.2; SD = 0.42; N = 10); infralabials 7–8 (x = 7.1; SD = 0.3; N = 11); temporals 1+2 (N = 17 sides), 1+3 (N = 3 sides); number of triads 6–8 (x = 7.2; SD = 0.8; N = 13); width of the central triad at the level of the midbody 5–10 scales (x = 8.0; SD = 1.41; N = 9); width of interspaces 6–12 scales (x = 8.8; SD = 1.92; N = 9); hemipenis (in situ) extends 13–15 subcaudal scales, and the retractor muscle extends 10–25 subcaudal scales.

Distribution (fig. 10): Distributed along the Equatorial forest associated to upper Orinoco and Negro Rivers, from southern Venezuela and Colombia to northern Brazil.