A new species of the ammonite genus Neochetoceras Spath (Oppeliidae) from the Hybonotum Zone (Lower Tithonian) of Southern Germany, with comments on the phylogeny of the genus

摘要

We here introduce a new species of the Submediterranean oppeliid genus Neochetoceras, N. mohri n.sp.,udrepresented by both macro- and microconchs. N. mohri n. sp. is better recorded than any other nominal species of thisudgenus and links the early representatives of the lineage with the type species, N. steraspis (Oppel). Possible phyleticudancestors and the biogeographic distribution are briefly discussed. The Neochetoceras succession in the uppermostudKimmeridgian (Beckeri Zone) to Lower Tithonian (Hybonotum and Mucronatum zones) is summarized.