The genus HerznachitesJeannet, 1951 is revised. It cannot be assigned to the family Oppeliidae as Jeannet believed. The result of a morphological analysis of the only specimen available to Jeannet is that it must be assigned to the genus Tornquistes of the family Pachyceratidae. The holotype of Tornquistes helveticus (Jeannet) is a macroconch. Another specimen that was found later is a microconch of the same species. The new specimen was found in situ and makes it possible to fix the age of the species to be of the Cordatum Subzone of the Cordatum Zone in the Early Oxfordian. © 1994, All rights reserved.
Gygi, R. A., Marchand, D., & Thierry, J. (1994). Tornquistes helveticus (Jeannet, 1951) (Ammonitina, Pachyceratidae) de l’Oxfordien inférieur du Jura Suisse; nom. nov. pro. “Herznachites” helveticusJeannet, 1951. Geobios, 27(4), 459–466. https://doi.org/10.1016/S0016-6995(09)90024-9