Widanelfarasia, a diminutive placental from the late Eocene of Egypt

The lower dentition of Widanelfarasia (new genus), a diminutive late Eocene placental from the Fayum Depression in Egypt, is described. Widanelfarasia exhibits a complex of features associated with incipient zalambdodonty and at least three unequivocal apomorphies [loss of P-1, an enlarged I-2 (rela tive to I-3), and a basal cusp on I-2], which provide weak support for its placement as a possible sister taxon of either a tenrecid-chrysochlorid cla de or of solenodontids. The former hypothesis gains additional support from biogeographical evidence, but both scenarios are currently tenuous as Wida nelfarasia is clearly not truly zalambdodont. Phylogenetic hypotheses posit ing affinities with tenrecids alone or chrysochlorids alone must invoke eit her convergent acquisition of zalambdodonty in these taxa or autapomorphic reversal in Widanelfarasia, Given these considerations, a relationship with more generalized taxa from the Laurasian Paleogene (e.g., geolabidids, nyc titheriids, leptictids) cannot yet be ruled out. Comparisons with other Pal eogene Afro-Arabian forms are generally inconclusive. A relationship with t he earlier Eocene Chambilestes from Tunisia-currently represented by a sing le specimen preserving P-4-M-3-seems possible based on the geometry and pre dicted occlusal relationships of these teeth, but cannot be confidently det ermined until these two taxa come to be represented by common diagnostic el ements. Todralestes (late Paleocene, Morocco) exhibits general phenetic sim ilarities to Widanelfarasia. but it is not yet known whether this taxon sha res any of Widanelfarasia's unequivocal dental apomorphies. Pending the rec overy of more informative material, we tentatively refer Widanelfarasia to Placentalia incertae sedis. Truly zalambdodont placentals remain conspicuou sly absent from the Paleogene of Afro-Arabia.