Drymarchon kolpobasileus, Krysko, Kenneth L., Granatosky, Michael C., Nuñez, Leroy P. & Smith, Daniel J., 2016

Krysko, Kenneth L., Granatosky, Michael C., Nuñez, Leroy P. & Smith, Daniel J., 2016, A cryptic new species of Indigo Snake (genus Drymarchon) from the Florida Platform of the United States, Zootaxa 4138 (3), pp. 549-569 : 564-566

Drymarchon kolpobasileus sp. nov.

Gulf Coast Indigo Snake

( Figures 10–11 )

Spilotes couperi (part) Cope 1860

Spilotes corais couperii (part) Lönnberg 1894 Compsosoma corais couperii (part) Cope 1900 Spilotes corais couperi (part) Brown 1901

Drymarchon corais couperi (part) Amaral 1929 Drymarchon couperi (part) Conant & Collins 1991 Drymarchon kolpobasileus Krysko et al. 2016 (this study)

Holotype. Florida Museum of Natural History, University of Florida (UF-Herpetology 52751); collected by Dennis M. Sargent in August 1981 on Mill Terrace and Riverwood Avenue, Sarasota, Sarasota County, Florida, USA (27.29291 N, 82.52453 W, datum WGS84). Attacked by domestic dog and brought to Sarasota Jungle Gardens where it died.

Paratypes. UF-Herpetology 55248, collected by T. Rooks on 6 June 1982 on State Road 24, 1.62 km SW State Road 345, Levy County, Florida (29.225295 N, 82.953708 W); UF-Herpetology 78797, collected by Paul Elliot on 15 November 1988 at the entrance of Upper Hillsborough Wildlife Management Area, Pasco County, Florida (28.35634 N, 82.12638 W); and UF-Herpetology 157096, collected by Joseph A. Wasilewski on 26 October 2006 at SW 204 Street and SW 134 Avenue, Miami, Miami-Dade County, Florida (25.57706 N, 80.40912 W).

Etymology. The Greek kolpo (meaning Gulf, referring to the Gulf of Mexico) and Greek basileus (meaning King) is used to form the composite noun kolpobasileus (Gulf King) , which is applied as a noun in apposition to the generic name Drymarchon . When sea levels were lower during the Pleistocene, D. kolpobasileus sp. nov. was the largest known snake inhabiting the subaerially exposed Florida Platform that extended much further westward than today. This species is still the largest native snake and king of the remaining exposed Florida Platform in the western peninsula and panhandle of Florida.

Distribution. Known to occur along the Gulf coast in Wayne County, Mississippi; and in Florida from Okaloosa County in the western panhandle, southeastward to Highlands, Putnam, and Seminole counties, eastward to Indian River County, and southward to Miami-Dade and Monroe counties on the extreme tip of the southern peninsula and Florida Keys. It is unknown if the single Pleistocene fossil from Dallas County, Alabama ( Dobie et al. 1996; Holman, 2000) is associated with Drymarchon kolpobasileus .

Diagnosis. Drymarchon kolpobasileus sp. nov. is distinguished by a suite of morphological features including relatively shorter and shallower head dimensions, relatively deeper and shorter 7th infralabial scales, and shorter temporal scales ( Fig. 5 ). Overall, the presence of a deep 7th infralabial scale provides the best univariate predictor of D. kolpobasileus sp. nov. ( Table 3 ). Based on both DNA ( Krysko et al. 2016) and morphology (specimens examined in this study) this species includes populations from the panhandle of Florida southeastward along the Gulf coast to southern peninsular Florida, including the Florida Keys.

Description of holotype. Adult male; Total Length 232.1 cm; Snout-vent Length 194.8 cm; Tail Length 37.3 cm; Head Length 68.5 mm; Head Width 36.2 mm. The relative head length (geometric shape variable; see Tables 2 and 3 ) is short (3.40) and relative head height is narrow (1.59). Supralabials 8/8 (left/right); Infralabials 9/9; Oculars 1+2/1+2; Temporals 2+2/2+2 (divided). The 7th infralabial is short (0.48) and broad (0.46) (geometric shape variable; see Tables 2 and 3 ) and the temporal scale is relatively long (0.85). The 5th and 7th supralabials are in contact with each other. Two pairs of chin shields, both of which are in contact with each other; posterior pair slightly narrower than anterior pair. The rostral visible from above, broader than high. Dorsal scales smooth and in rows at Mid-Body 17, Anterior 17 and Posterior 15; Ventral Scales 186; cloaca undivided; Subcaudal Scale Total 68 (all divided). The left hemipenis is everted.

The dorsum appears solid black from above. There is light pigment (likely reddish in real life) on the rostral, labials and chin shields that extend posteriorly onto the first two ventrals. Each ventral scale is mottled or bicolored with different degrees of black (posteriorly) and light colored (distally) pigmentation, with the last 8 ventrals predominantly black. Subcaudals are entirely black.

Intraspecific variation. Ventrals range from 181–194 (mean = 187, n = 71); subcaudals range from 60–71 (mean = 64, n = 36); supralabials are arranged 8/8 (n = 67), 7/8 (n = 1), and 7/7 (n = 3); infralabials are arranged 9/ 9 (n = 70) and 8/8 (n = 1); temporals are arranged 2 + 2 (n = 71), some individuals with smaller divided scales; oculars are arranged 1 + 2 (n = 71); and DSR are 15-17-15 (n = 29), 17-17-15 (n = 36), and 17-19-15 (n = 5).

Figures

FIGURE 5. Differences in infralabial and temporal scale morphology between the A) Eastern Indigo Snake, Drymarchon couperi (Holbrook, 1842), and B) Gulf Coast Indigo Snake, D. kolpobasileus, found in this study. Illustrations originally taken and modified from Cope (1900). Note that D. kolpobasileus has relatively deeper and shorter 7 th infralabial scales, shorter temporal scales, and overall shorter and shallower head dimensions (not depicted).

FIGURE 10. Holotype (UF-Herpetology 52751) of Gulf Coast Indigo Snake, Drymarchon kolpobasileus, from Sarasota County, Florida. A) dorsal and B) ventral views.

FIGURE 11. Holotype (UF-Herpetology 52751) of Gulf Coast Indigo Snake, Drymarchon kolpobasileus, from Sarasota County, Florida. A) lateral, B) dorsal, and C) ventral views of head region.