The Middle Devonian plant assemblage from Dechra Aït Abdallah (Morocco) revisited
Résumé
The composition of the allochthonous flora from Dechra Aït Abdallah (Central Morocco), initially described by Termier and Termier (1950), is reassessed from newly collected fossil material. Our work provides an updated taxonomic treatment of the plant remains. The flora comprises two lycophytes (including Leclercqia complexa), the probable iridopterid Anapaulia moodyi, and two aneurophytalean progymnosperms: Rellimia sp. and "Aneurophyton" maroccanum. Our revision confirms the Termiers' main conclusions that this Devonian flora is to date the most diverse and best known from Africa. Based on the complete paleontological evidence available from this locality, a Givetian age is as likely as an Eifelian age for the flora. The abundance of plant remains associated with the extreme scarcity of fertile organs may be accounted for by a taphonomic sorting, climatic conditions and/or specific ecological strategies. The flora of Dechra Aït Abdallah shows similarities with the Middle Devonian floras from the European part of Laurussia. This suggests that the paleogeographical position of Central Morocco permitted exchanges with Laurussia, and infers proximity of the latter with the north-western border of Gondwana during Middle Devonian times