. Bulletins of American paleontology. Jurassic Ammonites of British Columbia: Smith and Tipper 15 FANNIN FORMATION RENNELL JUNCTION MEMBER GHOST CREEK FORMATION I I I I I—r CARLOTTENSE SECTION E : MAUDE ISLAND Text-figure 1 1. —Lithostratigraphy and fossil localities of section E, Fannin Bay. southeast Maude Island. See Text-figure 6 for legend and Text-figure 20 for the fauna present. into the overlying Whiteavesi Zone. The long-ranging genus Metaderoceras is represented by the distinctive M. evolutum with its long spines and often looped, striate ribs. The Whiteavesi Zone fauna is considerab
. Bulletins of American paleontology. Jurassic Ammonites of British Columbia: Smith and Tipper 15 FANNIN FORMATION RENNELL JUNCTION MEMBER GHOST CREEK FORMATION I I I I I—r CARLOTTENSE SECTION E : MAUDE ISLAND Text-figure 1 1. —Lithostratigraphy and fossil localities of section E, Fannin Bay. southeast Maude Island. See Text-figure 6 for legend and Text-figure 20 for the fauna present. into the overlying Whiteavesi Zone. The long-ranging genus Metaderoceras is represented by the distinctive M. evolutum with its long spines and often looped, striate ribs. The Whiteavesi Zone fauna is considerably more diverse and characterized by a profusion of acantho- pleuroceratids, the first appearance of Dubariceras (D. silviesi) and the occurrence of coarse ribbed, robust forms of Metaderoceras. In the Freboldi Zone, above the range of the acanthopleuroceratids, diversity drops. Text-figure 12. —Lithostratigraphy and fossil localities of section F. the Forest Service Road 19 Quarry. See Text-figure 6 for legend and Text-figure 21 for the fauna present. again to levels comparable with the Imlayi Zone but, in marked contrast to the Imlayi Zone, the Freboldi Zone is amongst the thinnest Pliensbachian zones rec- ognized in the Queen Charlotte Islands. Dubariceras freboldi occurs throughout the zone and in the upper part of its range it frequently occurs with species of Reynesoceras. most of which range up into the Kunae Zone. The similarly thin Kunae Zone is remarkable for its quantum jump in diversity to the highest level seen in the Pliensbachian. Some of the increase is accom- plished by the appearance of a diverse suite of Fan- ninoceras species but most is caused by the appearance and rapid diversification of the hildoceratids and a proliferation of dactylioceratids ranging up from the Freboldi Zone. The upper part of the Fannin Formation yields three fauna! associations that represent the Pliensbachian- Toarcian transition. Species of Lioceratoides and Pro- togrammocera
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