24 Timothy S. Young and Joshua Laerm 



referred to a species with confidence. We follow Jones et al. (1992) 

 in their use of the familial name Muridae. 



Microtus pinetorum (LeConte) 

 Pine Vole 

 Material— Right M 2 , UGAMNH2128. 



Remarks — This molar compares well to modern Microtus 

 pinetorum. Regionally, the pine vole can be found in a wide range 

 of habitats from hardwood and pine forests to overgrown fields 

 (Golley 1962). The stratigraphic range is Sangamonian to Recent (Kurten 

 and Anderson 1980). 



Neofiber alleni True 

 Round-tailed Muskrat 



Material— right M 2 , UGAMNH2121; right M 3 , UGAMNH2123; 

 right M 3 , UGAMNH2122; maxilla, UF21293. 



Remarks — Neofiber alleni is a semi-aquatic mammal that prefers 

 permanent bodies of water with emergent aquatic vegetation (Frazier 

 1977). Although it has a restricted range today, essentially extreme 

 northern Florida and south Georgia, during the Pleistocene it ranged 

 as far west as Kansas (Hibbard 1943). It is reported from late Irvingtonian 

 to Recent (Kurten and Anderson 1980). The stratigraphic range is 

 Illinoian to Recent (Kurten and Anderson 1980). 



Ondatra zibethicus (Linnaeus) 

 Muskrat 



Material— Right dentary with M 1 AND M 2 , UGAMNH2120; 

 dentary, UF21292. 



Remarks — The muskrat, like the round-tailed muskrat, is a semi- 

 aquatic mammal that prefers permanent bodies of water (Nelson and 

 Semken 1970). There is not overlap in the range of the two species 

 today. However, Martin and Webb (1974) indicate they were sympatric 

 in at least two late Pleistocene Florida faunas, Devils Den and 

 Ichetucknee River. The occurrence of the two species in the St. Marks 

 River fauna is not overly suggestive that they were sympatric here in 

 the past because of the apparently heterochronous deposition at St. 

 Marks. Furthermore, although the muskrat does not presently occur in 

 the St. Marks River or Apalachicola River drainages, it is known 

 from the extreme western panhandle and the Upper Coastal Plain of 

 Georgia, a distance of 120 km. 



