Diplacanthiformes Berg, 1940

Hairapetian, Vachik, Valiukevičius, Juozas & Burrow, Carole J., 2006, Early Frasnian acanthodians from central Iran, Acta Palaeontologica Polonica 51 (3), pp. 499-520 : 508

Order Diplacanthiformes Berg, 1940

Remark.—Classification of the diplacanthids, including their higher taxonomical rank (order, suborder or family), has changed often since their assignment as a family of the Acanthodii by Woodward (1891). We will follow a proposal by Hanke et al. (2001) to revive the order Diplacanthiformes as a distinct assemblage of acanthodians which may or may not be closely related to armored “climatiiforms”. Characters by which the group is distinguished (when working on scales of articulated fish and in microremain assemblages) include the scale sculpture and histological structure of Diplacanthus − type ( Valiukevičius 1985, 1995). Diplacanthus − type histology is characterised by a crown with superpositional lamellae formed of simple mesodentine and long branching vascular canals, and an acellular base pierced by multibranched canals ( Valiukevičius 1995).