Article: Studies on Triassic fossil plants from Argentina. IV. The leaf genus Dicroidium and its possible relation to Rhexoxylon stems

The cuticle of four species of the genus Dicroidium is described. The material has been found in close association with Rhexoxylon stems in the locality of Ischigualasto, San Juan Province, Argentina. Two new combinations are proposed: Dicroidium zuberi (Szajnocha) and Dicroidium elongatum (Carruthers). It is proposed that Dicroidium leaves are related to Rhexoxylon stems (a) because they are associated in four Triassic localities of South Africa and Argentina, and (b) because there is a structural relation of both organs with the Palaeozoic pteridosperms.