Heptodon

Abstract: The early Eocene is an important time in Cenozoic history because it marked the height of global warming, coincident with significant reorganization of the mammalian biota. In North America, our understanding of mammalian diversity during this interval is largely limited to a fossil record south of the 49th Parallel. New discoveries in the early Eocene Driftwood Creek beds (Ootsa Lake Group), northern British Columbia (∼55°N) double the known diversity of Eocene mammals from this Canadian province and provide a window into the mammalian community that lived near the northernmost lake of the Okanagan Highlands, a series of Eocene lake deposits extending north-south from Republic, Washington, to Smithers, northern British Columbia. A diverse insect and fish fauna has been described from Okanagan Highlands Eocene lake shales, together with a diverse flora, interpreted as a cool upland forested landscape. We report the tapiroid cf. Heptodon and an erinaceomorph lipotyphlan Silvacola acares, gen. et sp. nov., from the Driftwood Creek beds. Presence of cf. Heptodon is consistent with the late early Eocene age of the Driftwood Creek beds determined by radiometric dating and palynology. Heptodon is otherwise known from Eocene localities in Wyoming and Colorado as well as Ellesmere Island in the High Arctic, whereas erinaceids are recorded from late Paleocene sites in Alberta, Saskatchewan, and the U.S. Western Interior and are relatively uncommon at Eocene sites in the U.S. Western Interior. Occurrence of cf. Heptodon at Driftwood Canyon supports the hypothesis proposed by others that tapiroids are proxies of densely forested habitats.

Abstract: Selenaletes scopaeus, a new genus and species of helaletid, is based upon a lower jaw fragment, probably from Lost Cabin beds, Wind River Basin, Wyo. Other material from Wyoming and Colorado provides knowledge of DP 4 and P 4 - M 3 . Generic diagnosis is: tiny, with relatively unmolariform premolars, lower molars similar to those of Heptodon except much smaller and with M 3 smaller than M 2 and lacking a hypoconulid. Selenaletes apparently is the smallest known perissodactyl.

Abstract: Pikes (Esocidae) are freshwater fishes now dwelling in northern hemisphere, most of them in cold waters south to the polar circle The family contains only one genus ( Esox) with five Recent species Among them two appear in China, one (Esox reicherti) in the northeastern part of China, in the Amur, Sungaria and Wusuli rivers' valley; the other (E lucius) in the Ertys River in Xin-jiang, northwestern China (Meng et al , 1995) The finds of the Late Cretaceous, Paleocene and Eocene pikes were so far restricted to North America although their distribution became much wider starting from the Oligocene (Cavender et al 1970; Sychevskaya, 1974, 1976; Gaudant, 1978, 1987; Wilson, 1980, 1981, 1984; Wilson et al, 1992; Grande, 1999) Thus, the fossil pike described in this paper is the first discovery of its kind from the early Eocene (or late Paleocene) outside of North AmericaThe specimens of pikes described in this paper were collected from the Member 2 of the Huang-xian Formation in Wali Coal Mine, Huangxian County, Longkou, Shandong Province (Fig 1) No remains of vertebrates other than fish were found from the Huangxian Formation Its correlation with the Wutu Formation in the nearby Wutu Basin was based on pollen (Paraalnipollenites-Betulaepolle-nites plicoides-Polypodiaceaesporites assemblage) and ostracods (e g Eucypris wutuensis) found in both formations The age of the Wutu Formation has been considered as early Eocene by the findings of Homogalax wutuensis and Heptodon niushanensis ( Chow and Li, 1965) A big variety of fossil mammals belonging to several big groups were discovered recently from the Wutu Formation Based on the study of the phylogeny of these groups combined with paleobiogeographic, paleoclimatic and biostratigraphic studies of North America and East Asia some researchers suggest the possibility of the age of the Wutu Formation as late Paleocene (Beard and Wang, 1995; Tong and Dawson, 1995; Beard, 1998; Beard and Dawson, 1999) Associated with the pike were disarticulated bones of amiids which are under description by the present authors