New Early Bathonian Bigotitinae and Zigzagiceratinae (Ammonoidea,Middle Jurassic)

Several tens of Lower Bathonian Bigotites from Digne-Castellane region (SE France) and Cabo Mondego area (Portugal) have been reviewed. Three species have been distinguished in the lowermost subzone of the Zigzag Zone (Parvum Subzone) just above the boundary Bajocian to Bathonian: B. diniensis Stura...

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Detalles Bibliográficos
Autor: Fernández López, Sixto Rafael
Tipo de recurso: artículo
Fecha de publicación:2007
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/50868
Acceso en línea:https://hdl.handle.net/20.500.14352/50868
Access Level:acceso abierto
Palabra clave:564.53(469)
Ammonites
Systematic palaeontology
Alpine Basin
Digne
Bas Auran
Lusitanian Basin
Cabo Mondego
Western Tethys
Paleontología
2416 Paleontología
Descripción
Sumario:Several tens of Lower Bathonian Bigotites from Digne-Castellane region (SE France) and Cabo Mondego area (Portugal) have been reviewed. Three species have been distinguished in the lowermost subzone of the Zigzag Zone (Parvum Subzone) just above the boundary Bajocian to Bathonian: B. diniensis Sturani [M+m], B. sturanii sp. nov. [M+m] and B. mondegoensis sp. nov. [M+m]. In the Bas Auran area, a chronocline from evolute, strongly ribbed and constricted forms (including B. sturanii and B. diniensis) to involute forms with blunt, moderately prominent ribbing and weak constrictions (including B. mondegoensis) can be recognized. The shared taxa B. mondegoensis sp. nov. and possibly B. diniensis Sturani permit detailed subdivision and correlation to be established between ammonite fossil assemblages of Parvum Subzone in the Lusitanian and Alpine basins. A separate genus of Zigzagiceratinae, Protozigzagiceras g. nov., is proposed to encompass P. torrensi (Sturani) as type species. These new palaeontological data about the youngest members of Bigotitinae and the oldest members of Zigzagiceratinae are of biochronostratigraphic importance for the subdivision and correlation of the basal Bathonian Zigzag Zone. Three successive biohorizons can be identified at the Parvum Subzone in Bas Auran (French Alpine Basin) and Cabo Mondego (Lusitanian Basin): Diniensis, Mondegoensis and Protozigzagiceras biohorizons.