systematics of snakes of the dipsas oreas complex - BioOne

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94 Bulletin Museum of Comparative Zoology, Vol. 158, No. 3 BMNH 1940.2.20.32 (Río Saloya, Pichincha Province, Ecuador. Female, 187 mm SVL). The dorsal pattern consists of regular, solid dark bands on pale ground color (no lightening of any dorsal bands). Bands are widest at midflank and narrow toward the ventrals and (less so) toward the vertebral scale row. Anterior bands are about 4 dorsal scale rows wide at their broadest point (the first band is 5 rows), narrowing to about 3 rows by midbody and continuing thus to the vent. Ventrally, the bands narrow to 3 scale rows wide on the anterior body, and to 2 rows wide on the posterior body; they encroach onto the outer edges of the ventrals. The top of the head down to upper edges of supralabials is solid dark gray with a few scattered very indistinct irregular paler areas. Supralabials are about 50% covered with dark markings, which is not especially concentrated along sutures lines. Infralabials are mostly dark. An indistinct pale collar about 2 scales wide is between the dark head cap and the first neck blotch. Ventral scutes are pale, with a pair of squarish blotches on the outer edges of most; the aligned blotches form irregular (and interrupted) series of broad lines on each side of the venter. Small juveniles of Dipsas elegans with solid dorsal bands might be confused with juveniles of D. oreas, which also have solid bands. However, D. elegans typically has many more bands than D. oreas (compare Figs. 11, 12, 17), and the head patterns of the two species also provide differential characteristics. The top of the head in juvenile specimens of D. elegans is patterned with dark gray (blackish in life) mottling → Figure 11. Juvenile patterns in Dipsas elegans (Boulenger). Top to bottom: USNM 210961, 192 mm SVL (Pichincha Province, Ecuador); USNM 210939, 199 mm SVL (Cotopaxi Province, Ecuador); USNM 210938, 184 mm SVL (Cotopaxi Province, Ecuador). The two smaller specimens (top and bottom) show no perceptible lightening of the central parts of the bands, whereas the lightening is very apparent in the middle specimen.
Dipsas oreas Complex in Ecuador and Peru • Cadle 95 Figure 12. Juvenile patterns in Dipsas elegans (Boulenger). Top: UMMZ 92073, 201 mm SVL (Imbabura Province, Ecuador) showing some lightening apparent in bands on the anterior body. Bottom: USNM 285957, 179 mm SVL (Pichincha Province, Ecuador), in which no lightening of the central parts of the bands is apparent. or reticulations on a pale brown or grayish ground color (the mottling may be so extensive as to color most of the top of the head with dark brown, especially in the parietal region). Juvenile D. oreas typically have paired dark elongate blotches in the parietal region, which is also characteristic of most adults (Figs. 16, 20; see also Cadle and Myers, 2003: 24, figs. 9, 10, 12). Moreover, juveniles of the two species differ by the other characteristics given in the diagnosis, including in loreal pattern (typically pattern 3 in D. elegans; typically pattern 1 or 2 in Ecuadorian D. oreas) and maxillary tooth number (Table 1). For example, maxillary tooth counts for seven juveniles of D. elegans (179–201 mm SVL) were 17–21; tooth counts for eight juveniles of D. oreas (150–193 mm SVL) were 12–14. Hemipenis The hemipenes of the holotype of Dipsas elegans (BMNH 1946.1.21.77) had
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systematics of snakes of the dipsas oreas complex - BioOne

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