Revision of Early Jurassic ammonoid types from the Persani Mts. (East Carpathians, Romania)

摘要

A large olistolith of Early Jurassic (Hettangian-Sinemurian) age exposed by the Tepei (Tope) Creek near Raco (Alsorakos) (Persani Mts.) has been a prolific source of ammonoids. This locality furnished type specimens of 24 nominal species and 13 subspecies, introduced by six different authors between 1866 and 1953. A comprehensive revision of the type material is presented. The majority of the original specimens are available, two are believed lost and another five could not be traced. Seven lectotypes are designated herein. Rediscovery of types for three species suppresses their previously chosen neotypes. Included in this material are the type species of four ammonoid genera. Confusion regarding the type species of Tragolytoceras is resolved by introducing T bonarellii n. sp. and suggesting it as the new type species of the genus. Stratigraphic distribution of some of the revised taxa is assessed on the basis of new, detailed collections from a similar olistolith exposed a few kin from the classical locality.