Upper and uppermost Famennian (Devonian) brachiopods from north-western France (Avesnois) and southern Belgium

Abstract

1. Introduction As noted by several authors (e.g. Gosselet, 1857; Cooper, 1954; Conil et al., 1986; Simakov, 1990; Mottequin et al., 2014), radiations were recorded among several brachiopod orders during the uppermost Famennian (Upper Devonian). Numerous productide, spiriferide, spiriferinide and rhynchonellide genera first appeared during this interval and are characterized by morphological features heralding the Mississippian brachiopod faunas. Brice et al. (2013) recently stressed that the brachiopod data related to the uppermost Famennian of the Avesnois (north-western France) (Fig. 1), which is the historical type area of the Strunian (Streel et al., 2006), strongly need to be updated in order to detail the consequences of the Hangenberg Crisis (Kaiser et al., 2011, 2015). In this area, the last comprehensive study on uppermost Famennian brachiopods dates back to Dehee (1929). His study, based on Gosselet, Delepine, Carpentier and Dehee’s material, is poorly stratigraphically constrained and some elements of the fauna described by Dehee (1929), such as the atrypides, were not obtained from the uppermost Famennian (Copper, 1986). The brachiopods were subsequently and partly revised by Vandercammen (1956), Legrand-Blain (1991), Brice (1997), Nicollin (2004, 2008) and Brice et al. (2013). The situation is more critical in southern Belgium where the mixed carbonate-siliciclastic Strunian facies are relatively similar to those occurring in the Avesnois. In Belgium, the vast m