Quelques Asaphidae (Trilobita) de la Formation de Saint-Chinian, Ordovicien inférieur, Montagne Noire (France): Systématique et paléoenvironnements
文摘
The study of asaphid trilobites from the Saint-Chinian Formation, Lower Ordovician, Montagne Noire, includes the systematic revision of the genus Paramegalaspis Thoral in Jaanusson, 1956. P. immarginata (type species), P. nov. sp. aff. P. immarginata and Asaphellus frequens from the Saint-Chinian and La Maurerie Formations are described. The species globosus is removed from this genus and P. illaeniformis is considered as a junior synonym of P. immarginata. Genal caeca occur in Paramegalaspis immarginata, a feature described for the first time in Ordovician asaphids. Asaphids are one of the major components of the Saint-Chinian Formation fauna which apparently corresponds to an outer shelf environment.
