Palaeogeography and palaeoecology of early Floian (Early Ordovician) cephalopods from the Upper Fezouata Formation, AntiAtlas, Morocco

This is the first description of Ordovician cephalopods from Morocco. Although their occurrence has been known for a long time, only a poorly preserved conch from the late Katian of Ikhf n’Ouzerg (central Anti-Atlas) was described as “Orthoceras hastile Barrande” by Termier & Termier (1950). In some cases Ordovician cephalopods were mentioned within faunal lists without classification (e.g., Guti rrez-Marco 2003; Destombes 2006a; Van Roy et al. 2010). Indeed, the lack of earlier works on Moroccan cephalopod assemblages does not reflect their absence or rarity. It rather is an expression of a neglect of the group by many palaeontologists working in the region. Generally, the Ordovician cephalopods of the high latitude margins of Gondwana are poorly known and, where known, often are in need of revision. Of those high latitudinal assemblages most recently revised or newly described in detail (Marek et al. 2000; Gnoli & Pillola 2002; Evans 2005; Kr ger & Evans 2011), all seem to be characterized by the presence (often in abundance) of specific forms that are rare or absent in low palaeolatitude regions. Contrary to the situation in most other high latitude (peri-)Gondwanan regions (e.g., Algeria, Bohemia, France, Spain), the first reports of Ordovician faunas in the Anti-Atlas, Morocco are relatively recent (Bigot & Dubois 1931; Choubert 1952; Choubert et al. 1953). Intensive field work achieved by Jacques Destombes between 1959 and 1985 during the campaign of 1 : 200,000 mapping of the whole Anti-Atlas lead to a much improved stratigraphic framework, and to the collection of abundant fossil material (Destombes 1962, 1971; Destombes et al. 1985). In particular, extremely