Mammals of the Ardis Local Fauna 



L9 



Q\ 



% % 



D. E. 



3 cm 



_i 



Fig. 3. Comparisons of recent squirrel humeri to the Ardis fossil specimen. 

 A) Spermophilus franklini (USNM-54153) B) Spermophilus lateralis (USNM- 

 250744) C) Tamiasciurus hudsonicus (USNM-505592) D) Spermophilus 

 tridecemlineatus (USNM-255383) E) Spermophilus tridecemlineatus Ardis 

 local fauna (.175) F) Tamias striatus (USNM-347965). 



Sciurus carolinensis - Gray Squirrel 

 Material: 1 right humerus proximal half (.172); 1 right tibia proximal 

 half (.173); 1 left tibia distal one third (.174). 



Remarks: The material is distinguished from Sciurus niger by its smaller 

 size and is indistinguishable from recent material of the gray squirrel. 

 This species ranges throughout the eastern half of the United States 

 north into Canada, where it inhabits deciduous and coniferous forests, 

 timbered streams, and bottomlands (Webster et al. 1985). 



This is the first fossil record of the gray squirrel from South 

 Carolina. 



Spermophilus tridecemlineatus - Thirteen-lined Ground Squirrel 

 Material: 1 left humerus (.175). 



Remarks: In comparisons with recent humeri of mustelids, microtines, 

 cricetids, and a variety of ground squirrels, all others were eliminated 

 because of various morphological inconsistencies. Tamias striatus hu- 

 meri vary significantly from S. tridecemlineatus with differently shaped 

 proximal condyles and distal articulations. The humeral shaft is no- 

 ticeably more slender with respect to the total length in Tamias striatus 

 than in S. tridecemlineatus. Tamiasciurus hudsonicus humeri have a 



