Triphyllopteris collombiana: A Clarification of the Generic Concept Based on Rediscovered Specimens from Kossberg BEI Plauen, Germany, and a Reassignment of the North American Species of Triphyllopteris to Genselia gen. nov.

Abstract

A whole frond reconstruction of Triphyllopteris collombiana Schimper is presented based on specimens from Kossberg bei Plauen, Saxony, Germany. New information is derived from fragments of a frond apex, a basal portion of the rachis, and a medial fragment that demonstrate the transition in pinnule shapes from base to apex. Because Schimper's original material was lost in a fire without being refigured, and because this material clearly exhibits a spatial arrangement of pinnule shape variation that conforms precisely to Schimper's diagnosis, I have designated the largest of the Kossberg specimens as a neotype. An emended generic diagnosis clarifies the overall frond shape and architecture and defines precisely the range and spatial pattern to pinnule shape variation. With this clarification of the intent of Schimper's original diagnosis, it is now possible to assess whether specimens that subsequent workers have assigned to Triphyllopteris do in fact conform to Schimper's original concept of the genus. Spe...