Los Ammonoideos del Cenomaniense superior al Santoniense de la plataforma nord-castellana y la cuenca navarro-cántabra Parte I. BioestratigrafIa y sistemática: Phylloceratina, Ammonitina (Desmocerataceae y Hoplitaceae) y Ancyloceratina

Abstract

Upper Cenomanian to Santonian ammonites from the Noth-Castillian Platform and the Navarro-Cantabrian Basin. Part I. Biostratigraphy and Sistematics Phylloceratina, Ammonitina (Desmocerataceae and Hoplitocerataceae) and Ancyloceratina.

This work, based an the Doctoral thesis of the autor (Santamaria, 1991),deals on the sistematics and biostratigraphy of the upper Cenomanian to Santohanammonite faunas from the northern part of the North-Castillian platformand the southern part of the Navarro-Cantabrian basin.
In this first part twenty ammonite species are described, belonging to thesuborders Phylloceratina (1), Ammonitina (8, only incluiding Desmocerataceaeand Hoplitocerataceae superfamilies), and Ancyloceratina (11), being one ofthem new: Scaphites (S.) bituberculatus. In the second part superfamily Acanthocerataceae (50) will be described.
By the stratigraphical distribution of those ammonite species the following biostratigraphical units have been recognized:
For the Upper Cenomanian, an Eucalycoceras rowei assemblage, an interval with no record and a Neocardioceras sp. assemblage.
For the Turonian, a Choffaticeras quaasi assemblage and a Mammites nodosoides interval biozone for the Lower Turonian, a Kamerunoceras turoniense, Romaniceras kallesi and R. deverianum assemblages for the Middle Turonian and a Subprionocyclus sp. gr. neptuni-hitchinensis assemblage for the Upper Turonian.
For the Coniacian, an interval with no record for the Lower Coniacian, a Metatissotia ewaldi interval biozone for the Middle Coniacian and a Prionocycloceras iberiense, Protexanites bourgeoisi and Hemitissotia sp. interval biozones and Gauthiericeras margae and Forresteria?(H.) aff. nicklesi subzones for the Upper Coniacian.
For the Santonian, a single extent biozone with Placenticeras polyopsis. All these biostratigraphical units have been compared and correlated with the standard ammonite sequence proposed by Kennedy (l948b), and with the Northern Spain zones defined by Wiedmann (1960, 1964, 1978b) and Wiedmann & Kauffman (1978).