Taxonomy, biostratigraphy and paleoecology of lower Silurian conodonts from the Anse a Pierre-Loiselle Formation, Gaspe Peninsula, Quebec.

Abstract

Conodonts of late Llandovery age have been collected from the Anse a Pierre-Loiselle Formation, the deposition of which represents a deepening episode in the generally shallow deposition of the Chaleur Group in southern Gaspe. The fauna is dominated numerically by elements assigned to Panderodus, Oulodus?, and Ozarkodina with elements of Aulacognathus, Carniodus, Distomodus, Johnognathus, Kockelella, Pterospathodus, and Walliserodus as well as rate or indeterminate taxa. One genus is new, represented by one species: Digitodontus bellistriatus. Other new species include: Apsidognathus sulcatus, Pseudooneotodus pyramis and Pterospathodus? ceragnathoides. Based on these faunas the unit is considered to represent deposition of Llandovery C$\sb6$--early Wenlock age. Due to the low abundance of zonal indicator species Pterospathodus celloni and P. amorphognathoides, a new taxon range zone is established to encompass the total range of the new species P.? ceragnathoides which is locally abundant. The position of the Llandovery-Wenlock boundary remains unclear. (Abstract shortened by UMI.)