Biostratigraphy of the Lower Ordovician chitinozoa of western Newfoundland, Canada.

摘要

The Cow Head Group of western Newfoundland, lying exposed within shoreline sections between Bonne Bay and Portland Creek, represents an allochthonous sediment apron or toe deposit at the base of an ancient carbonate-rich continental margin. While it has been studied extensively for a variety of fossil species, few accounts exist for chitinozoa in this stratigraphically important section. For this study, a detailed analysis of samples from 6 sections across the Lower Ordovician Cow Head Group recovered 32 species of well-preserved chitinozoan. In addition, 22 taxa of uncertain specific designation have been identified which represent 9 genera (Amphorachitina, Belonechitina, Conochitina, Desmochitina, Eremochitina, Lagenochitina, Laufeldochitina, Rhabdochitina, and Tanuchitina), and include several species that have never been documented from western Newfoundland.; From the present study it is clear that the distributional controls on chitinozoa within the Cow Head Group are indeed complex, and likely influenced by an array of sedimentological and biological processes. (Abstract shortened by UMI.)