University of Kansas Publications Museum of Natural History
Volume 13, No. 3, pp. 73-84, pls. 9-12, 3 figs. August 16, 1960
A New Subspecies of Slider Turtle (Pseudemys scripta) from Coahuila, México
BY JOHN M. LEGLER
University of Kansas Lawrence 1960
University of Kansas Publications, Museum of Natural History
Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Robert W. Wilson
Volume 13, No. 3, pp. 73-84, pls. 9-12, 3 figs. Published August 16, 1960
University of Kansas Lawrence, Kansas
PRINTED IN THE STATE PRINTING PLANT TOPEKA, KANSAS 1960
28-3860
A New Subspecies of Slider Turtle (Pseudemys scripta) from Coahuila, México
BY
JOHN M. LEGLER
In September, 1958, the author and two colleagues collected a large series of Pseudemys in small ponds and in a river in the basin of Cuatro Ciénegas, Coahuila. The specimens prove to represent a previously unrecognized subspecies of Pseudemys scripta. The subspecies is named in honor of Edward Harrison Taylor who has contributed more than any other person to our present knowledge of the herpetofauna of México.
Pseudemys scripta taylori new subspecies (Pls. 9-12, Figures 1 & 2)
Holotype.—Univ. Kansas Mus. Nat. Hist., No. 46952, adult female, alcoholic; 16 km. S Cuatro Ciénegas, Coahuila, México; 6 September 1958; original number 1694 John M. Legler.
Paratypes.—A total of 52 specimens as follows (numbers or series of numbers marked with an asterisk are for specimens prepared as dry shell with soft parts in alcohol): KU 46932-4*, 46949-51, 46953-67, 46969 (females), 46935*, 46936-48, 46968 (males), same data as holotype, 6 to 8 September 1958; UU 3416 (male), same locality, 29 to 30 July 1959; KU 46971, 46973* (females), 46972 (male), 46970, 46974 (juveniles), 6 mi. W Cuatro Ciénegas, 3 to 6 September 1958; IU 43585, 43587-9 (females), 43586, 43590 (males), same locality, 11 July 1958; CNHM 55655 (female), same locality, 22 August 1939; KU 46976 (female), Río Chiquito, 10 km. S Cuatro Ciénegas, 9 September 1958; UU 3415 (female), 8.5 mi. SW Cuatro Ciénegas, 1 August 1959.
Diagnosis.—A subspecies of Pseudemys scripta most closely resembling P. s. elegans, but differing from that subspecies in having: 1) extensive black plastral pattern, all parts of which are interconnected, covering approximately half of plastron; 2) tendency toward melanism, in large adults of both sexes, especially noticeable on posterior part of plastron; 3) cutting edge of lower jaw coarsely serrate; 4) tendency for femoral edges of plastron to be reflected ventrally, especially in males; and, 5) pectoral scute longer than gular.
Table 1. Measurements (in millimeters) of the Holotype (46952) and Nine Adult, Topotypic Paratypes of Pseudemys scripta taylori New Subspecies. Height Was Measured in a Vertical Line from the Center of the Plastron.
Description of holotype (measurements given in Table 1).—Carapace oval in dorsal aspect, slightly narrowed behind, nearly straight across anterior margin, bluntly serrate behind; shell deep, highly arched in cross section; height of shell 53 per cent of width; surface of shell having longitudinal striations; middorsal keel weakly developed, scarcely discernible except on third central lamina; lateral margin of carapace not at all reflected, posterolateral margins flared outward; central laminae all broader than long, the first urn-shaped.
Ground color of carapace (hereinafter, colors are those of preserved specimen) dark olive; upper surface of each marginal scute having round or oval black mark, two such marks on each marginal of first pair; marks on margin of anterior half of carapace having pale orange-yellow borders, marks more posteriorly having indistinct borders or no border; upper surface of carapace having numerous, irregularly arranged black marks on a faint reticulum of pale lines; one or two large oval marks on each lateral scute arranged more or less vertically, other marks on laterals irregular in size and arrangement; central scutes having three to five longitudinally arranged, narrow black marks on each scute.
Ground color of plastron pale yellow, anterior half extensively marked with black along laminal seams; all plastral markings interconnected; undersurfaces of marginals on anterior half of shell having pale centers; undersurfaces of posterior marginals and posterior half of plastron solid black.
Plastron more or less evenly rounded in front, slightly indented on gular border; posterolateral free edge of plastron reflected slightly downward; posterior border of plastron having wide shallow anal notch; plastral laminae, in order of length—abdominal, anal, pectoral, gular, femoral, humeral; abdominal lamina longer than combined lengths of pectoral and humeral or humeral and gular.
Head moderately wide; snout slightly pointed in dorsal view, curving evenly backward and downward from nostrils in profile; upper jaw notched in middle, cutting edges finely and unevenly serrate, crushing surfaces having distinct ridge bearing fine denticulations but no large teeth; cutting edges of lower jaw coarsely and evenly serrate, tooth at symphysis relatively large; raised ridges of lower crushing surfaces each having low blunt tooth and many fine denticulations.
Major markings of head and neck as follows: narrow stripe beginning at posterior edge of eye and extending downward and backward (across tympanum) on side of neck to shoulder (stripe wider behind than at origin); wide stripe from lower posterior corner of eye extending downward, across mandibular articulation (and below tympanum) on throat to shoulder (wider at origin than behind); postorbital mark, four to five millimeters wide, approximately 26 millimeters long, connected to eye by narrow isthmus anteriorly and continuous with narrow stripe on upper part of neck posteriorly; stripe on mandibular symphysis widened and bifurcated posteriorly, its two branches enclosing one wide and two narrow stripes; wide stripe beginning in middle of mandibular ramus and running backward to point below mandibular articulation on each side; top of head, sides of snout, and areas between above-mentioned major stripes, marked with numerous, fine, often indistinct pale lines.
Pale dorsal stripe on fleshy portion of each finger, those of second and fourth fingers continuous to mid-humeral region, those of other fingers broken on anterior face of antebrachium; upper and lower pale stripes of antebrachium joined in mid-humeral region.
Coloration of living specimens.—Ground color of soft parts dark olive to slate gray or black; ground color of carapace olive to slate gray; ground color of plastron pale yellow, markings blackish, tinged with brown in younger specimens, sooty black in most adults. Postorbital mark red; other markings on soft parts cream to buffy yellow.
Geographic range.—Pseudemys scripta taylori is known only from ponds, and the Río Chiquito in the basin of Cuatro Ciénegas. The discovery of taylori brings to six the number of valid subspecies of scripta known in México (elegans, gaigeae, hiltoni, nebulosa, ornata, and taylori) and to three (elegans, gaigeae, and taylori) the number known in Coahuila. My own studies of these six subspecies indicate that they are, beyond reasonable doubt, members of a single polytypic species (scripta). I tentatively follow Williams (1956:153) in rejecting "cataspila" as an invalid name.
Three specimens of Pseudemys scripta obtained by Robert G. Webb in the Río Chiquito at a point 8 mi. W of Nadadores, 2100 ft., where the river flows out of the basin of Cuatro Ciénegas, have many characteristics in common with taylori, but resemble elegans closely in several characters as follows: no extensive melanism; plastral markings tending to be brownish; anterior plastral markings smudgelike, isolated or nearly isolated; markings on lateral scutes tending to have vertical, linear arrangement; cutting edge of mandible weakly serrate; femoral edges of plastron not reflected ventrally; one or more fine, pale lines between two major stripes on antebrachium; gular longer than pectoral in one specimen, longer than femoral in both specimens. The nature of these specimens suggests that parts of the Río Salado drainage north and east of Cuatro Ciénegas are in a zone of intergradation between taylori and elegans. I have examined what I consider to be typical examples of P. s. elegans from the region of Múzquiz (CNHM 28843-45, 55625-45), and from Don Martín Reservoir (KU 33524). These localities are, respectively, approximately 70 miles north-northeast and 100 miles east-northeast of Cuatro Ciénegas. The specimens from Múzquiz are presumably the same that Carr (1952:262) treated as "... elegans-cataspila intergrades, but with a strong leaning toward eastern elegans...." Populations of P. scripta in central eastern Coahuila (between the above-mentioned localities and Cuatro Ciénegas) probably are a conglomerate of only two subspecies (elegans and taylori), not including gaigeae (as was suggested by Hamilton, 1947:65 and by Carr, op. cit.:241, map 17;262).
