The occurrence of Gastrioceras in the Moroccan Meseta and mid‑Bashkirian ammonoid palaeogeography

The Late Carboniferous ammonoids Gastrioceras listeri (Sowerby, 1812) and Gastrioceras angustum Patteisky, 1965 are reported from Ighr ou Hammoud in the vicinity of Dechra Aït Abdallah (central Moroccan Meseta). The assemblage shows very close relationships to those from the South Portuguese Zone, the British Isles and the Rhenish Mountains, suggesting a contiguous epicontinental sea. These occurrences differ from those of the American Midcontinent on the species level within Gastrioceras, but much more prominently in the significantly greater diversity of the assemblages from Arkansas and Oklahoma. These differences are better interpreted as differences in environment than with palaeogeography.

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