1 6 Curtis C. Bentley and James L. Knight 



Peripherals, femora, humeri, and mandible - These elements are tenta- 

 tively referred to this species because they compare most closely to Recent and 

 fossil C guttata. 



Remarks: The spotted turtle ranges from northern Illinois into Ohio and Ontario, 

 east to Maine and New York, and south along the Atlantic Coastal Plain into 

 northern Florida (Conant and Collins 1991). Clemmys guttata occurs most com- 

 monly in bogs or marshy pastures, but it also can be found in woodland streams. 

 It favors habitats with soft substrates. C. guttata is frequently found away from 

 water, but even so it is the least terrestrial of the three eastern species of Clem- 

 mys (Ernst and Barbour 1989). The fossil spotted turtle remains from the Ardis 

 local fauna represent the oldest known material of this species (Bentley and 

 Knight 1993), and the first fossil record for the eastern United States. Holman 

 (1990) reports a right epiplastron from a 6,000-year-old fauna near Lansing, 

 Michigan. Interestingly, Ernst and Barbour (1989) noted a relationship between 

 this turtle and the burrows of muskrats, which the turtles apparently use for esti- 

 vation and hibernation sites. Fossil muskrats were the most common mammals 

 found at the Ardis site (Bentley et al. 1994) and are believed to have used the 

 solution cavities as burrow sites. This may help to explain the abundance of this 

 turtle at the Ardis site. 



Clemmys muhlenbergii - Bog turtle (Schoepff, 1801) 



Material: An individual consisting of a partial carapace (nuchal, 1st and 2nd left 

 costals and peripherals, 2 peripherals, numerous shell fragments) and plastron 

 (both epiplastra, and partial hyoplastron) (.429). 



Isolated elements: 2 nuchals (.430-.431) ; 2 right epiplastra (.433-.434). 



Characters used for identification: C. muhlenbergii fossils were distinguished 

 from other emydid turtles based on characters listed in previous sections, along 

 with additional nuchal and sulci characters given by Bentley and Knight (1993) 

 (Fig.5). 



Remarks: The soft bottoms and slow moving waters of swamps, bogs and 

 marshes are typical aquatic habitats of the bog turtle (Ernst and Barbour 1989), 

 but this turtle can also be found on land. Clemmys muhlenbergii has a patchy 

 distribution in the Northeast, and ranges as far south as northern Georgia and 

 extreme northwestern South Carolina. This disjunct spatial pattern has been 

 interpreted as suggesting a larger former range (Smith 1957). The fossil evi- 

 dence from the Ardis site suggests that the species' range extended at least 250 

 km farther southward during the late Pleistocene. 



