A reconsideration of Wattieza Stockmans (here attributed to Cladoxylopsida) based on a new species from the Devonian of Venezuela

A single small plant fragment from the Middle Devonian of Belgium, first illustrated by Stockmans as Wattieza givetiana, is redescribed. It consists of a small central axis bearing on it whorls of four several-times bifurcate laterals that are terminally recurved. One tip is here shown to have attached one elongate ellipsoid sporangium. More abundant Middle Devonian fossils from Venezuela have similar characteristics, although they are more robust. They, together with more simple sterile examples, are demonstrated to be attached laterally and irregularly to large axes that are themselves found distal to a digitate division of a substantial branch with an enlarged base. All branches, axes and the central axes of the lateral branching systems are covered in small tangentially elongate depressions. These characteristics, taken together, demonstrate that Wattieza is a large plant of similar habit to Pseudosporochnus Potonie et Bernard. Wattieza joins Lorophyton Fairon-Demaret et Li, Calamophyton Krausel et Weyland and Pseudosporochnus as morphologically well-circumscribed Devonian members of the phylogenetically important plant group Cladoxylopsida. Wattieza casasii Berry sp. nov, is erected to accommodate the Venezuelan material. (C) 2000 Elsevier Science B.V. All rights reserved.