Tremadocian (Ordovician) trilobites from the Brabant Massif (Belgium): Palaeogeographical and palaeoecological implications

A poorly diverse trilobite assemblage is described from the Tremadocian strata (Tangissart Member of the Mousty Formation; Chevlipont Formation) of the Brabant Massif. These specimens represent so far the oldest trilobite record from Belgium. The recorded taxa, identified as Platypeltoides cf. croftii, Macropyge? sp., and Asaphidae indet., resemble contemporaneous trilobites from other parts of Avalonia (e.g., Wales, Shropshire) as well as some others from high-latitude Gondwana (Morocco). The nileid species P. cf. croftii suggests that the Tangissart Member of the Mousty Formation was likely deposited in deeper offshore environments on the open shelf of Avalonia. Morphological similarities between P. cf. croftii from the Brabant Massif, P. croftii from the UK, and P. magrebiensis from Morocco suggest close faunal interchange across the narrow Rheic Ocean.