28 C. C. Bentley, J. L. Knight, and M. A. Knoll 



route instead of along the Gulf Coast corridor, as attributed to the 

 fossil remains from the Haile 14A fauna (Webb 1974). Fossil locali- 

 ties reporting S. tridecemlineatus (Kurten and Anderson 1980) and 

 other fossils collected from the Ardis site, in particular a portion of 

 the turtle fauna (Bentley and Knight, submitted), strongly suggests 

 the existence of a northern corridor(s) onto the Atlantic Coastal Plain. 

 This would be a logical pathway for those glacially displaced species 

 of the Northeast found at the Ardis site. 



Blarina brevicauda, Microtus pennsylvanicus, and Synaptomys 

 cooperi are interpreted as "boreal" or "cool climate" components of 

 the Ardis fauna, based on modern distribution and habitat orientation 

 (Hoffman and Jones 1970, Graham 1976, Webster et al. 1985). Neofiber 

 alleni is considered a sub-tropical or "warm climate" species based on 

 modern distribution and fossil records (Martin and Webb 1974, Frazier 

 1977, Kurten and Anderson 1980, Holman 1985). 



Those extinct species collected from the Ardis fauna with extant 

 genera or families primarily tropical to sub-tropical in distribution 

 include: Tremarctos floridanus, Palaeolama mirifica, Conepatus robustus, 

 Tapirus veroensis, and the family Hydrochoeridae. Holmesina septentrionalis 

 has also been interpreted as indicating a mild climate (Kurten and Anderson 

 1980). 



Generalization of ecological needs of an extinct species based on 

 the needs of extant relatives cannot always be considered reliable. 

 However, when several such groups are geologically recent, are in a 

 single locality, and represent a short depositional time interval, as at 

 the Ardis site, these assumptions become more credible. 



The modern Coastal Plain fauna of South Carolina has six 

 species of microtines, three species of shrews, and two mole species 

 (Webster et al. 1985). Fossil remains of both mole species and two of 

 the three shrew species were collected from the Ardis fauna, along 

 with eight microtine species. Greater microtine densities in late Pleis- 

 tocene faunas have been correlated with reduced temperature and 

 moisture gradients (Graham 1976). This is also true for shrew species 

 (Graham 1976), but we did not observe it in the Ardis fauna. The 

 reduction in the number of shrew species at the Ardis site is probably 

 a result of collection bias and not a true reflection of the shrew 

 populations. 



Martin (1968) suggested that the distribution of M. pennsylvanicus 

 is limited mostly by warmer temperatures and drier summers, but also 

 by the presence of Sigmodon hispidus, which was inexplicably absent 

 from the Ardis fauna. The mean July temperature for the southern 

 boundary of M. pennsylvanicus is 23.9 ± 1.1 C (Martin 1968), and 



