I thank Carla Crook and Dr. Steve Etches from The Etches Collection
for giving guidance on the collection area.
United Kingdom and Ireland
Geological Time: Jurassic Upper Jurassic
Kimmeridge Clay Formation
the raw material was collected and the specimen was extracted and photographed by
Michael Hesemann
Forma 2, with constrictions between chambers at the last and/or initial part.
The identification is based upon:
, : Orbigny A. D. d'. (1850-1852). Prodrome de paléontologie stratigraphique universelle des animaux mollusques et rayonnés, faisant suite au cours élémentaire de paléontologie et de géologie stratigraphiques. Paris: Masson. vol. 1 [January 1850 ("1849")]: lx + 394 pp.; vol. 2 [November 1850]: 427 pp.; vol. 3 [1852]: 196 pp. + Table alphabétique et synonymique des genres et des espèces: 189 pp; addend Plate , Fig.