The early radiation of Cetacea took place in the eastern Tethys region (Thewissen, 1998; Williams, 1998), and included the endemic Indo-Pakistani family Remingtonocetidae. In India, remingtonocetids are only known from Kachchh (=Kutch, Gujarat, western India), the classical marine middle Eocene sequence for the Indian subcontinent, which has yielded the genera Kutchicetus, Remingtonocetus, and Andrewsiphius (Sahni and Mishra, 1975; Kumar and Sahni, 1986; Bajpai and Thewissen, 1998). In Pakistan, two remingtonocetids, Remingtonocetus and Dalanistes, have been described by Gingerich et al. (1995) from the Sulaiman Range. A third genus, Attockicetus, is known from the Kala Chitta Hills (Thewissen and Hussain, 2000).

Despite the rapidly expanding knowledge of Lower Devonian brachiopod faunas of the Western Cordillera of Canada (Lenz, 1976, 1977a, 1977b, 1982; Ludvigsen, 1970; Perry, 1984; Perry and Lenz, 1978; Perry et al., 1974, 1981), equivalent data on coeval gastropod faunas from this region are non-existent; to date, no publications have appeared in which gastropods have been described. Blodgett et al. (1988, table 1) provided faunal lists for two Lower Devonian localities in Western Canada: 1) Lochkovian-Emsian age collections from the Mackenzie Mountains, Northwest Territories, collected by the late D. G. Perry as part of his Ph.D. dissertation (Perry, 1984); and 2) an early Emsian collection from the Mt. Lloyd George area, British Columbia. We are currently examining the gastropod material recovered by A. C. Lenz from his richly diverse collections in the Royal Creek area, Yukon Territory, equivalent in age to those gathered by D. G. Perry from the Mackenzie Mountains. This note is the first of several papers focused on these paleobiogeographically significant faunas, and it is our desire to ultimately make clear the character of this Early Devonian province, which appears to include strata of British Columbia, Yukon and Northwest Territories, as well as the non-accreted portion of adjacent east-central Alaska.