Geology, Paleoenvironment, and Age of Birket Qarun Locality 2 (BQ-2), Fayum Depression, Egypt

Abstract

Vertebrate paleontological research in the Fayum Depression began in 1879, with Georg Schweinfurth’s recovery of whale and fish fossils on the island Geziret el-Qarn in Birket Qarun (Dames, 1883; Schweinfurth, 1886). In later years Schweinfurth worked north of the lake, in part within the uppermost levels of the Birket Qarun Formation that are exposed to the south of (and stratigraphically below) the site of the Qasr el-Sagha Temple, but he is not known to have collected any vertebrate fossils from those beds. Subsequent exploration by Hugh Beadnell, and later Richard Markgraf, led to the discovery of fragmentary remains of the cetacean Basilosaurus isis from near this stratigraphic horizon on the northwest side of Birket Qarun (Andrews, 1904; Stromer, 1908; see also Gingerich, 2008), but no vertebrate fossils were reported from sediments exposed on the northeast side of the lake until late in the 20th century, when a single premolar of the proboscidean Moeritherium was described (Holroyd et al., 1996). In the year 2000, paleontological reconnaissance in the sediments exposed along the ‘‘plain of Dime’’ led to the identification of a number of new vertebrate fossil localities (Fig. 1), most of which preserve fragmentary remains of proboscideans (Barytherium and Moeritherium), sirenians, and whales. One locality situated on the northeast side of Birket Qarun, now called Birket Qarun Locality-2 or BQ-2, initially produced surface finds of creodont postcrania, a basicranium and partial mandible of Barytherium, a partial mandible and postcrania of Moeritherium, and a small placental petrosal. Subsequent quarrying anddry screening at BQ-2 from2001 to 2005 has revealed craniodental and postcranial remains of numerous small mammals, including primates, hyracoids, herodotiines, ptolemaiids, anomaluroid and hystricognathous rodents,