HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

The ammonites of the Les Ferres Aptian Basin (Lower Cretaceous, Southeast of France): the genus Toxoceratoides (Ancyloceratina, Helicancylidae)

Abstract : Toxoceratoides (Ancyloceratina, Helicancylidae) is a lower Aptian (Lower Cretaceous) small heteromorph ammonoid mainly known by small samples of fragmentary specimens. In the present work, we study a sample of 145 specimens of this genus from the Deshayesites forbesi, Deshayesites deshayesi and Dufrenoyia furcata zones (lower Aptian) of the vicinity of the village of Les Ferres (southeastern France). The taxa recognized (in stratigraphic order) are: Toxoceratoides sp., Toxoceratoides royerianus (d’Orbigny, 1842) and Toxoceratoides rochi Casey, 1961a, Casey, 1961b. Their ontogenetic sequence is described; the intraspecific variability of Toxoceratoides rochi is considerable and it concerns adult size, coiling, duration of the ontogenetic stages and ornamentation. No sexual dimorphism is recognized. The main evolutionary pattern of the genus consists in the replacement of primitive ribs (here named ‘royerianus ribs’) by derived ribs (‘rochi ribs’) on the flexus and retroversum. The genus Toxoceratoides could be used as a biostratigraphic tool.
Complete list of metadata

Cited literature [11 references]  Display  Hide  Download

https://hal-insu.archives-ouvertes.fr/insu-02966450
Contributor : Isabelle Dubigeon Connect in order to contact the contributor
Submitted on : Wednesday, October 14, 2020 - 8:33:11 AM
Last modification on : Wednesday, May 11, 2022 - 4:04:59 AM
Long-term archiving on: : Friday, January 15, 2021 - 6:17:14 PM

File

bersac-bert-2020.pdf
Files produced by the author(s)

Identifiers

Citation

Stéphane Bersac, Didier Bert. The ammonites of the Les Ferres Aptian Basin (Lower Cretaceous, Southeast of France): the genus Toxoceratoides (Ancyloceratina, Helicancylidae). Cretaceous Research, Elsevier, 2021, 118, pp.104661. ⟨10.1016/j.cretres.2020.104661⟩. ⟨insu-02966450⟩

Share

Metrics

Record views

110

Files downloads

63