Acanthohoplites sp.

Frau, Camille, 2023, Upper Aptian Ammonites From Roussillon, Southern France, Fossil Imprint 79 (1), pp. 89-101 : 98

Acanthohoplites sp.

Text-fig. 4m

M a t e r i a l. Specimen LGB-ROU.11d ( Text-fig. 4m ).

D e s c r i p t i o n. Specimen LGB-ROU.11d is a small, incomplete ammonite. Ribbing of its body chamber, occupying one quarter of the outer whorl, consists of the alternation of strong primary ribs with distinctive elongated tubercles, and few, commonly two, atuberculate secondaries irregularly arranged. The tubercles of the primary ribs divide into two, rarely three, branches over the venter. Primary ribs can be followed by an approximated secondary rib, so that they mimic a constriction. All ribs cross the venter.

D i s c u s s i o n. Specimen is tentatively assigned to the genus Acanthohoplites , since its ribbing closely matches the Abichi stage of the type species Acanthohoplites aschiltaensis ( ANTHULA, 1900) sensu Frau (2023) .

O c c u r r e n c e. In the Vocontian Basin of SE France, Acanthohoplites has its lowest occurrence datum between the first (FA1) and second (FA2) black shale levels of the Fallot episodes ( Dauphin 2002). This falls in the lower part of her Colombiceras tobleri Zone , which is the lower part of the upper Epicheloniceras martini Zone of Dutour (2005).

Figures

Text-fig. 4. Roussillon’s specimens assigned to Egoianiceras angulatum (EGOIAN, 1969).