Mammals of the Ardis Local Fauna 27 



and 2) depositional and behavioral biases; the smaller taxa, particularly 

 those that used this site as a shelter or in hunting, should be represented 

 in disproportionately higher numbers when compared to the megafauna. 

 Behavioral and environmental factors influence the occurrence of the 

 smaller taxa which could easily enter the cavities from the surface. 

 Furthermore, some taxa may have been concentrated in the stomachs 

 of predators who were subsequently entombed in the cavities. The 

 above-mentioned factors, excluding predation, but including other taphonomic 

 factors, especially the size-restrictive nature of the cavity openings, 

 would govern the lower frequency of the larger megafauna occurrence 

 in the cavities. Therefore, the species composition most likely is not 

 proportional to its true occurrence in this particular Pleistocene community. 



Relatively large faunal diversity may give a reasonably reliable 

 picture of the surrounding habitat (Guilday 1962). The taxa of the 

 Ardis local fauna represent a diversity of ecological niches including 

 semi-aquatic forms (Castor, Lontra, Ondatra, Tapirus, and Mustela 

 vison), arboreal forms (Glaucomys volans, Sciurus carolinensis), marsh 

 and meadow inhabitants (Synaptomys, Microtus, Oryzomys), grassland 

 or prairie forest transition inhabitant (Spermophilus tridecemlineatus), 

 and the large grazers and browsers (Palaeolama, Bison, Equus, Odocoileus, 

 Megalonyx, Mammut, and Mammuthus), suggesting that the Ardis fauna 

 sampled an ecological mosaic of community types. The depositional 

 features and fauna suggest a composite conifer and hardwood forest, 

 interspersed or bordered by a grassland/meadow, possibly giving way 

 in low-lying areas to a marsh or bog, with a permanent nearby stream 

 or river. 



Hypothesized changes in vegetation during the late Pleistocene 

 (Dreimanis 1968), with climatic conditions unlike any experienced in 

 North America today (COHMAP Members 1988), are reflected in the 

 extralimital tropical to boreal species found in the Ardis fauna. 



Of the 43 mammalian species collected from the site, 27 are 

 extant, 21 still occurring in the area today. Of the six extant extralimital 

 taxa, four have more northern affinities, one a midwestern affinity, 

 whereas only one has a range well south of the Ardis site. Of the 16 

 extinct taxa, five have affinities considerably south and west of the 

 Ardis locality (Kurten and Anderson 1980, Martin 1978). 



The Ardis mammal fauna exhibits a mixture of southern, west- 

 ern, and northern forms, resulting from the radiation and convergence 

 onto the lower Atlantic Coastal Plain of taxa migrating along the 

 Gulf Coast corridor (Webb 1974) and taxa migrating from the north- 

 west Appalachian Mountains region. It is plausible that Spermophilus 

 tridecemineatus may have entered South Carolina from a northern 



