Fig. 1. Geographical distribution of ''apternodontids'' (sensu lato) in North America. Acronyms are given in parentheses for institutions that have made significant collections from each locality. Each number represents a locality, listed in alphabetical order, known to have produced ''apternodontid'' fossils, as follows: 1: Badwater (CM), 2: Banjo Quarry (YPM­PU), 3: Bates's Hole (AMNH, UW), 4: Big Badlands (USNM, YPM), 5: Cameron Spring, Beaver Divide (USNM), 6: Canyon Ferry (CM, USNM), 7: Cook Ranch (MPUM, CM), 8: Cypress Hills, Lac Pelletier (RSM), 9: Diamond O Ranch (MPUM, CM), 10: Dilts Ranch (UW), 11: Douglass Creek Basin (FMNH), 12: East Fork Basin (AMNH), 13: Easter Lily (MPUM, CM), 14: Elderberry Canyon (USNM), 15: Emerald Lake (AMNH), 16: Eureka Valley Road (MPUM, CM), 17: Fitterer Ranch (USNM), 18: Flagstaff Rim (USNM, AMNH), 19: Fort Union Fm., Clark's Fork Basin (UMMP), 20: Fremont Butte (DMNH), 21: Harshman Quarry (UW), 22: Highway 10N (MPUM, CM), 23: Horsetail Creek (DMNH), 24: Iliff (FMNH, KU), 25: Little Pipestone Creek (MPUM, CM, AMNH), 26: Lonetree, Wyoming (UCM), 27: McCarty's Mountain (FMNH, MPUM, CM), 28: Mellinger (UCM), 29: Pipestone Springs (MPUM, CM, AMNH), 30: Powder River Basin (UCM), 31: Powder Wash (CM), 32: Red Mound (TMM), 33: Raben Ranch (SDSM), 34: San Diego (UCMP), 35: Sand Wash Basin (DMNH), 36: Seamen Hills (AMNH), 37: Tabernacle Butte (CM, UMMP), 38: Torrington (MCZ).