St. Marks River Fauna 29 



Remarks — The morphology of the elements is consistent with its 

 identification as Mammut americanum. Dreimanis (1968) suggested that 

 M. americanum inhabited coniferous forests. The stratigraphic range is 

 early Blancan to Wisconsinan (Kurten and Anderson 1980). 



Family Elephantidae 

 Mammuthus jeffersonii (Osborn) 

 Jefferson's Mammoth 

 Material — Tooth fragments, UGAMNH1607-1611; tooth fragments, 

 UF21259-21262, 21264-21266; mandibular symphysis, UF21263. 



Remarks — The morphology of the tooth fragments and 

 mandibular symphysis is consistent with its identification as 

 Mammuthus jeffersonii. Jefferson's mammoth probably inhabited open 

 grasslands (Stock 1963, Harrington et al. 1974). The stratigraphic range 

 is Illinoian to Wisconsinan (Kurten and Anderson 1980). 



Order Perissodactyla 



Family Equidae 



Equus sp. indet. 



Horse 



Material — left astragalus, UGAMNH1035; cervical vertebra, 

 UGAMNH1170; left upper cheek tooth, UGAMNH1045; right upper 

 cheek tooth, UGAMNH1031; right lower cheek tooth, UGAMNH1048; 

 cheek tooth, UGAMNH1046, 1047, 1062; right deciduous P 2 , 

 UGAMNH1042; left deciduous P 2 , UGAMNH1061; right cuneiform, 

 UGAMNH1049; left femoral head, UGAMNH1034; right distal 

 humeral epiphysis, UGAMNH1054; left I 3 , UGAMNH1036; right 

 I 2 , UGAMNH1041; lower incisor, UGAMNH1056; left I 3 , UGAMNH1059; 

 left I 1 , UGAMNH1060; incisive fragment, UGAMNH1032; left upper 

 molar, UGAMNH1038; right M 2 ,UGAMNH1039; right M 3 , 

 UGAMNH1044; left M 3 , UGAMNH1057; upper molar fragment 

 UGAMNH1029; left navicular, UGAMNH1063; medial phalanges 

 UGAMNH1030, 1050, 1053; distal phalanx, UGAMNH1051; proximal 

 phalanx, UGAMNH1055; left P 2 , UGAMNH1037; right P 2 , 

 UGAMNH1040; left upper premolar, UGAMNH1043; right lower 

 premolar, UGAMNH1058; left scapula, UGAMNH1052; sesamoid, 

 UGAMNH1033; medial phalanx, UF21228; teeth, UF21229-21238; teeth 

 UF21240-UF21254; cheek tooth, axis, and pelvis, UF21297. 



Remarks — Equus is well represented in St. Marks River. A portion 

 of the material is poorly mineralized and probably represent 

 contaminants of the modern E. caballus. However, the majority of 

 elements are well fossilized, and it is likely that most of the material 



