Les ammonites traditionnellement regroupées dans la sous-famille des Bouleiceratinae (Hildoceratidae, Toarcien) : aspects phylogénétiques, biogéographiques et systématiques

The genera usually considered into the Bouleiceratinae subfamily belong in fact to different lineages of the Hildoceratidae family. An approach using paleogeographical, stratigraphical and morphological arguments on one hand and a cladistic approach on the other hand have allowed to separate 3 clusters with different paleogeographical and stratigraphical localisations. These are:

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the Bouleiceratinae s.s. (genera Bouleiceras, Nejdia and Kohaticeras) from lower Toarcian;

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the Leukadiellinae (genera Leukadiella and Renziceras) from middle Toarcian;

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and the Paroniceratinae (genera Frechiella, Paroniceras and Oxyparoniceras) from middle and upper Toarcian. These latters are mainly present and the Tethyan domain, but are also known in the NW of Europe and especially in France where new populations have been studied in the Causses, in the centre-ouest and in the Lyon area. New taxa have been erected here: Oxyparoniceras (Neoparoniceras) nov. sub. gen., O. (N.) brocardi nov. sp. and O. (N.) sciaui nov. sp.