Phytogeographical implications of the probable occurrence of the gnetalean plant Welwitschiophyllum in the Late Cretaceous (Cenomanian) of Africa

Abstract

A new fossil plant specimen, identified as a probable leaf of Welwitschiophyllum Dilcher et al. (2005) is reported from the Gara Sbaa Member of the? Lower Cenomanian to Turonian Akrabou Formation of south east Morocco. Previously Welwitschiophyllum was only known from the Early Cretaceous of Brazil, and this discovery considerably extends its temporal and geographical ranges. It is identified on account of its characteristic elongate shape, entire margins, parallel venation and an arcuate margin of the base. The new specimen expands our knowledge of the poorly-known Gara Sbaa florule, and is the first possible gnetophyte recorded from this locality, adding crucial knowledge to African Cretaceous floral diversity. Comparison with similar leaf types from the Aptian-aged Nova Olinda Member of the Crato Formation of north east Brazil hint at a xerophytic or perhaps halophilic floral province in equatorial Gondwana prior to the opening of the South Atlantic Ocean. This province is at least 3500 km from north to south.