Bransonelliformes Hampe and Ivanov, 2007a

Johnson, Gary D. & Thayer, David W., 2009, Early Pennsylvanian xenacanth chondrichthyans from the Swisshelm Mountains, Arizona, USA, Acta Palaeontologica Polonica 54 (4), pp. 649-668 : 662

Order Bransonelliformes Hampe and Ivanov, 2007a

Remarks.— Hampe and Ivanov (2007a) suggested this taxon to include Bransonella and Barbclabornia , both known only from isolated teeth. The teeth in these genera are quite dissimilar (compare fig. 1 A–D with fig. 1 E–H in Hampe and Ivanov 2007a), despite their attempt to draw analogies. It is beyond the scope of this paper to deconstruct their reasoning (e.g., their choice of character−states; Rodrigo Soler−Gijón, personal communication, October 2007), because analysis of other genera would be necessary. And until skeletal information (even dorsal spines) is discovered, such an assignment may be premature. However, for the present, Hampe and Ivanov’s (2007a) taxonomy is followed here and discussed further below.