A reconsideration of Hyenia elegans Krausel et Weyland and Hyenia 'complexa' Leclercq: Two Middle Devonian Cladoxylopsids from western Europe

Two taxa of Middle Devonian Cladoxylopsida from localities in Belgium and G ermany are redescribed. A counterpart of one of the missing type specimens of Hyenia elegans Krausel et Weyland from Kirberg, Germany, demonstrates th at rather than having simple forked fertile appendages (as apparent from th e type description), more complex fertile units were present; these consist ed of two daughter segments (resulting from a proximal dichotomy), each of which bore three pairs of elongate sporangia on short recurved stalks proxi mal to a terminal bifurcation. Specimens from Oe, Belgium, informally refer red to as Hyenia 'complexa' by Leclercq, were shown to have a similar ferti le organ that lacked the tuft of filiform extensions previously believed to be present. The parallel axes of this plant are now interpreted to be deri ved from a digitate branch rather than from a horizontal rhizome. Both taxa , H. elegans and H. 'complexa,' therefore demonstrate fertile appendage mor phology and other characters that are typical of the Middle Devonian cladox ylopsid Calamophyton primaevum Krausel et Weyland, which has priority.