Revisiting the Rebreuve plant assemblage from the Lower Devonian of Artois, northern France

Abstract

ABSTRACT French Lower Devonian floras are rare, especially compared to certain other Western European countries. In this study, we reassess an assemblage collected in the 1930s in the Rebreuve quarry (Pas-de-Calais, northern France). We describe new features in several taxa and update taxonomic names from original descriptions. For instance, re-examination of vegetative remains previously described as Psilophyton princeps, led to the discovery of fertile structures allowing us to refer these specimens to Sawdonia. In total, this flora consists of 10 taxa, including up to four different Psilophyton species, such as P. parvulum. Other taxa include Danziella artesiana, Drepanophycus cf. spinaeformis, Sporogonites exuberans and some specimens of Taeniocrada and Sciadophyton, revealing a diverse Lower Devonian plant assemblage. The Rebreuve assemblage represents a typical Emsian flora from Laurussia and bears striking resemblance with coeval Belgian assemblages. Previous palynological investigations, in addition to the similarities with well-dated Belgian floras, suggest an early Emsian age for this assemblage. The paleogeographical implications of findings are discussed.