‘ Hyenia’ vogtii Høeg from the Middle Devonian of Spitsbergen—Its morphology and systematic position

Abstract

Certain characters of the branching patterns of Hyenia vogtii Høeg ( Pseudosporochnus vogtii (Høeg) Schweitzer) from the Middle Devonian (Givetian) of Spitsbergen, Svalbard, are clarified. Branching is predominantly whorled. In a whorl, dichotomous appendages form the majority of the subtending organs, but the position of an appendage may be taken by a branch. This pattern is typical of plants of the Middle and Late Devonian group Iridopteridales and fits within the generic circumscription of the genus Ibyka Skog and Banks to which it is transferred under the name Ibyka vogtii (Høeg) Berry comb. nov.