40 Michael E. Seidel 



assignment to P. concinna. Further indication that these turtles are ref- 

 erable to P. concinna comes from discriminant analysis of cranial morph- 

 ology. Skulls of New River turtles are phenetically close to P. c. con- 

 cinna and P. c. suwanniensis, and broadly separated from all forms of 

 P. floridana (Fig. 5). 



Recent evidence of fertile eggs, numerous sight records of basking 

 adults, discovery of bones 700 to 800 years old, rediscovery of a 

 museum specimen collected in 1934, and extensions of the known range 

 22 km south of Bluestone Reservoir to Giles County, Virginia and 2 km 

 northeast of Bluestone Reservoir in the Greenbrier River, West Virgi- 

 nia, support the hypothesis that cooters in the New River represent a 

 natural, established population. Assuming an origin not involving 

 human interference, there are two possible avenues for dispersal that 

 could have allowed P. concinna to enter the New River. The first is an 

 early Pleistocene invasion from the Mississippi Valley (embayment 

 region) through the old Teays River, which followed the course of the 

 present Kanawha and New Rivers (Fig. 1). An argument for this route 

 is supported by the occurrence of cooters referrable to the Mississippi 

 Valley subspecies P. c. hieroglyphica in the lower Kanawha River, 

 Mason County, and Mud River, Cabell County, West Virginia (Seidel 

 and Green, in press). To examine this relationship, twelve New River 

 specimens were compared to seven adult and two subadult P. c. hiero- 

 glyphica from Reelfoot Lake, Tennessee. New River P. concinna differ 

 from these turtles in having: a lower carapace with the highest point at 

 the middle; shell not usually constricted at the region of the sixth mar- 

 ginal; fewer concentric light lines on the carapace; dark markings on the 

 bridge that frequently contact submarginal blotches; alveolar surface of 

 lower jaw relatively narrow; and fewer and broader stripes on the head 

 and neck, especially ventrally. These characteristics are more typical of 

 the Piedmont subspecies, P. c. concinna (Carr 1952; Mount 1975). 

 Although the New River is a Kanawha River tributary, it is separated 

 from the Ohio and Mississippi River valleys (inhabited by P. c. hiero- 

 glyphica) by Kanawha Falls (Fig. 1). This falls is believed to be one of 

 the largest natural river barriers east of the Rocky Mountains (Jenkins 

 et al. 1971). Furthermore, rapids and cataracts in New River Gorge just 

 above Kanawha Falls provide an effective barrier to fish distribution 

 between the Kanawha and New Rivers (Hocutt et al. 1979). Therefore, 

 preglacial dispersal of cooters from the Mississippi Valley into the upper 

 Teays (New) River may not have been possible. 



A second potential avenue for dispersal of P. concinna is over the 

 Atlantic-Ohio divide of Virginia and North Carolina. Wright (1934), 

 Thompson (1939), Dietrich (1959), and Ross (1969), reported late Pleis- 

 tocene stream captures of the New River by the James and Roanoke, 

 two rivers inhabited by P. c. concinna in the Piedmont (Martof et al. 

 1980; and Fig. 1). Comparisons of New River P. concinna to five adult, 



