Chitinozoaires de l'Ordovicien supérieur - formations de Vauréal et de Ellis Bay - de l'Ile d'Anticosti, Québec

Chitinozoans from the Vaureal and Ellis Bay Formations have been studied. An analysis of the chitinozoan microfauna indicates that the Vaureal Formation is characterized by several species of the genus Hercochitina. The Ellis Bay Formation, on the other hand shows a less diversified assemblage in which Conochitina gamachiana is dominant. An important variation of the microfauna is observed in beds at the base of Member 6 of the Ellis Bay Formation. This variation possibly indicates the Ordovician-Silurian boundary on Anticosti Island. Four new chitinozoa species, Conochitina gamachiana, C. concava, Ancyrochitina longispina and Lathrochitina concinna are described.