98 



J. Alan Holman and Jerry N. McDonald 



Fig. 7. Map showing the most northern area (crosshatched) where all members 

 of the Saltville herpetofauna (dot) may be found living together today. 



Unit Wl, lying astride the Wisconsin-Holocene boundary (ca. 

 10,500 to 10,000 B.P.), consists of an organic-rich mud at SV-1 that 

 contains remains of Bufo woodhousei fowleri and Chelydra serpentina. 

 The boundary between W2 and Wl was distinct below where USNM 

 404730 and USNM 404741 were found, which suggests that these iso- 

 lated remains were transported with the mud when — or deposited 

 after — it moved, rather than being moved upward from the underlying 

 lake deposit by bioturbation. Conceivably, the mud encompassing these 

 specimens was a littoral deposit displaced by the downslope movement 



