0000000000178695
AUTHOR
Robert Busnardo
Une discordance ante albienne datée par une fauned'Ammonites et de Brachiopodes de type téthysien au Mexique central
Resume Au Nord de Leon (Guanajuato), la discordanced'un horizon carbonate neritique sur un substratum volcano-sedimentaire tectonise materialise une phase tectonique majeure dans la cordillere ouest mexicaine. L'âge albien superieur de ce temoin recifal est etabli par une petite faune d'Ammonites appartenant aux genres Eohypoturrilites, Pseudouhligella, Salaziceras et Eutrephoceras, et des Terebratules du genre Moutonithyris. La position de ce gisement montre l'extension vers l'ouest des facies carbonates connus sur la plate-forme est mexicaine.
Problems in the identity of "Crioceras" barremense Kilian, 1895 (Ancyloceratida, Late Barremian), and their proposed resolution
17 pages; The study of "Crioceras" barremense KILIAN was undertaken as a part of the revision of the Hemihoplitidae. This species was considered "classic" and has been used as the index of an Upper Barremian subzone; this usage raises a number of problems. The type specimen from Tyrol was a fragment described and illustrated by UHLIG as Crioceras sp. ind. aff. roemeri. This specimen could not be retrieved, and a topotype could not be collected. Our study revealed that there is both a biostratigraphic hiatus and important differences between conceptions of this species: (1) that ascribed UHLIG's type specimen (Upper Barremian, Tyrol), (2) KILIAN's concept of the specimen he found and named "…