Aspidoceratidae ZITTEL, 1895


Fauna

Pairs

Perisphinctidae

Aulacostephanidae

Aspidoceratidae

Family Aspidoceratidae

The ornamentation of Aspidoceratidae is characterized by the transformation of the primary ribs into 1-2 lines of tubercles of variable aspect and position. According to the authors, this family is divided into several subfamilies : Peltoceratinae, Euaspidoceratinae, Aspidoceratinae... The species illustrated on this page belong all to the subfamily of Aspidoceratinae.

Orthaspidoceras lallerianum (d'Orb.) juv. Ø 117 mm
Orthaspidoceras schilleri (Opp.) M Ø 176 mm

Genus Orthaspidoceras

The macroconch is a medium-sized or large ammonite (200-250mm), thick and relatively involute with more or less depressed, subtrapezoid or subquadratic rounded shape. The ornamentation made up of a line of coarse tubercles, sometimes thorny and accompanied by fine streaks.

The microconch is a small-sized form (100-150mm) with weakly marked dimorphic characters. This genus contains only 3 species, namely: O lallerianum (d'Orb.), O schilleri (Opp.) and O. orthocera (d' Orb.).

Aspidoceras group caletanum (Opp.)

These ammonites probably come from the thethysian groupe A. acanthicum (Opp.). During the upper Kimmeridgian, they colonized the different French-German provinces.

The macroconch has a relatively large and moderately evolute shell (300mm). Its section is subquadratic and its ornamentation consists of 2 lines of thorny tubercles. These tubercles are often linked together by weak ribs.

The microconch is twice smaller than its dimorphic partner, but with rather comparable ornamentation, shape and coiling.

Orthaspidoceras orthocera (d'Orb.) m Ø 104 mm
Aspidoceras caletanum (Opp.)
M Ø 251 mm
Aspidoceras quercynum (Hantzp.) M Ø 142 mm