Article: New Late Devonian genera and species of tornoceratid goniatites

A brief review is given of the evolutionary relationships of generic groups in the Devonian goniatitc family Tornoceratidae (Ammonoidea) as an introduction to the description of two new genera, Falcitornocerai and Crassotomocems, from levels around the Frasnian-Famennian boundary. Species and subspecies of these genera are described from western Europe and Crassotornoceras is recorded also from North America. A detailed sequence of faunas with Falcitornoceras is described from the Montagne Noire across the Frasnian-Famennian boundary. Statistical data regarding the ontogeny of both genera are provided and a description is given of the early stages of Falcitornoceras which demonstrates the marked change in ornament at the end of tk ammonitella stage, of the type already known in other members of the family. The following new species and subspecies are described: C. annissi, F. falciculum falciculum, F. falciculum constriction, and F. falciculum wagneri.