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SB 1A/Live Oak

The SB 1A/Live Oak LF was collected from a limestone mine just north of Live Oak in Suwannee County, northern Florida. Arikareean fossils were derived from fine-grained sediments filling a solution feature developed in marine Oligocene limestone (Frailey 1978). Frailey (1978) reported seven species of mammals from the SB 1A/Live Oak LF: four carnivores (the amphicyonid Mammacyon cf. M. obtusidens, the canids ?Mesocyon and Phlaocyon, and the mustelid Paroligobunis frazieri), the sciurid rodent Protosciurus, a horse, and the small camelid Nothokemas waldropi. Subsequent screenwashing led to the recovery of a diverse fauna of amphibians, reptiles, and small mammals. New additions to the SB 1A/Live Oak mammalian fauna include: the marsupial Herpetotherium, a vespertilionid bat, the small musteloid carnivores Palaeogale minuta and Arikarictis chapini, an undescribed entoptychine rodent, the large eomyid rodent Arikareeomys, and several species of the heteromyid rodent Proheteromys. Only two bat fossils have been recovered from this site, a lower molar of a small vespertilionid and an unidentified distal radius.

Frailey (1978) considered SB 1A/Live Oak to be late Arikareean and Tedford et al. (1987) and Albright (1998) placed this fauna in the early late Arikareean (Ar3), whereas Hayes (2000) thought this site was late early Arikareean (Ar2). The rodents Protosciurus and Arikareeomys and the tiny camelid Nothokemas waldropi are restricted to early Arikareean faunas in Florida. Protosciurus is found in Chadronian through early Arikareean faunas in the western US. Arikareeomys occurs in three other Florida Arikareean faunas, Cow House Slough, White Springs, and Buda. The only non-Florida record of this genus is from the McCann Canyon LF in Nebraska, originally placed in Ar3 (Korth 1992), but now thought to correlate with the Ar2 Monroe Creek Fauna (Tedford et al. 1996). SB 1A/Live Oak shares three species with the early Ar2 Brooksville 2 LF, the small carnivores Palaeogale minuta and Arikarictis chapini, and an undescribed entoptychine rodent. SB 1A/Live Oak LF is here placed in the late early Arikareean (late Ar2, 24-26 Ma), and is considered correlative with the White Springs LF, younger than Brooksville 2 and older than Buda.