New Hystricognathous Rodents from the Early Oligocene of Central Libya (Zallah Oasis, Sahara Desert): Systematic, Phylogenetic, and Biochronologic Implications

ABSTRACT Four fossil rodent taxa are described from a new locality in the Oligocene Continental and Transitional Marine Deposits outcropping in the vicinity of Zallah, Sirt Basin, central Libya. These rodents belong to the infraorder Hystricognathi Tullberg, 1899, and are distributed amongst four genera (Metaphiomys Osborn, 1908; Phiocricetomys Wood, 1968; Talahphiomys Jaeger et al., 2010; and Neophiomys , new genus) that include one new species, Phiocricetomys atavus, and one new combination, Neophiomys paraphiomyoides (Wood, 1968), formerly Phiomys paraphiomyoides Wood, 1968. The specimens described here have profound implications for the phylogenetic and systematic status of early hystricognathous rodents and paleogeographical debates regarding their origin. Based on a cladistic analysis, Waslamys attiai Sallam et al, 2009, is transferred to the genus Protophiomys Jaeger et al., 1985, as Protophiomys attiai (Sallam et al, 2009), new combination. That species is the type species of the monobasic genus W...