TABLE 1. Upper molar metrics (mm) for apatemyids (Apatemys and Sinclairella) from Sioux County, Nebraska. Sources: 1, this study; 2, Clemens (1964); and 3, Ostrander (1987). Abbreviations: L, maximum anterior-posterior length; W, maximum transverse width.
| Specimen number | Locality | Species | Tooth | L | W | Source |
| UMPC 13937 | Sand Creek | S. dakotensis | M1 | 4.1 | 3.69 | 1 |
| UMPC 14860 | Whitehead Creek | S. dakotensis | M1 | 3.68 | 3.43 | 1 |
| RAM 381 | “anthills” sec. 26 | S. dakotensis | M1 | 4.1 | 3.5 | 2 |
| UMPC 14862 | Sand Creek | S. dakotensis | M2 | 3.73 | 4.63 | 1 |
| RAM 1674 | “anthills” sec. 26 | S. dakotensis | M2 | 3.4 | 4.2 | 2 |
| UMPC 14190 | Whitehead Creek | Apatemys sp. | M2 | 2.8 | 3.3 | 1 |
| UMPC 14863 | Sand Creek | S. dakotensis | M3 | 3.51 | 4.89 | 1 |
| UMPC 14864 | Sand Creek | S. dakotensis | M3 | 2.74a | 3.4a | 1 |
| UMPC 14191 | Whitehead Creek | Apatemys sp. | M3 | 1.8 | 2.8 | 1 |
aApproximate measurement based on damaged specimen.
TABLE 2. Lower molar metrics (mm) for apatemyids (Apatemys and Sinclairella) from Sioux County, Nebraska. Sources: 1, this study; 2, Clemens (1964); 3, Ostrander (1987). Abbreviations: L, maximum anterior-posterior length; Tri W, maximum transverse width across the trigonid; Tal W, maximum transverse width across the talonid.
| Specimen number | Locality | Species | Tooth | L | Tri W | Tal W | Source |
| UMPC 14861 | Orella Road | S. dakotensis | m1 | 3.48 | 1.88 | 2.24 | 1 |
| UMPC 13938 | Sand Creek | S. dakotensis | m1 | 3.44 | 1.79 | 2.07 | 1 |
| UMPC 14270 | Whitehead Creek | S. dakotensis | m1 | 3.45 | 1.57 | 2.08 | 1 |
| RAM 1000 | “anthills” sec. 26 | S. dakotensis | m1 | 3.5 | * | 2.2 | 2 |
| SDSM 10241-a | Raben Ranch | S. dakotensis | m1 | 3.51 | 2.01 | 2.4 | 3 |
| SDSM 10241-b | Raben Ranch | S. dakotensis | m1 | 3.61 | 1.96 | 2.36 | 3 |
| SDSM 10242 | Raben Ranch | Apatemys sp. | m1 | 2.62 | 1.54 | 1.72 | 3 |
| UMPC 13601 | Sand Creek | S. dakotensis | m2 | 3.26a | 1.84a | 1.98a | 1 |
| UMPC 13869 | Sand Creek | S. dakotensis | m2 | 3.5 | 2.74 | 2.59 | 1 |
| UMPC 14866 | Whitehead Creek | S. dakotensis | m2 | 3.65 | 2.42 | 2.36 | 1 |
| UMPC 14865 | Whitehead Creek | S. dakotensis | m2 | * | 2.3 | * | 1 |
| RAM 598 | “anthills” sec. 26 | S. dakotensis | m2 | 3.8 | * | 2.6 | 2 |
| RAM 1001 | “anthills” sec. 26 | S. dakotensis | m2 | 3.6 | * | 2.6 | 2 |
| RAM 1079 | “anthills” sec. 26 | S. dakotensis | m2 | 4 | * | 2.8 | 2 |
| RAM 3013 | “anthills” sec. 26 | S. dakotensis | m2 | 3.6 | * | 2.8 | 2 |
| SDSM 10243 | Raben Ranch | S. dakotensis | m2 | 4.07 | * | 3.05 | 3 |
| SDSM 10245 | Raben Ranch | S. dakotensis | m3 | 6.16 | 2.82 | 2.62 | 3 |
*Measurement not available. Clemens (1964) provided only length and maximum width. aApproximate measurement based on damaged specimen.
