Description
Original diagnosis after Grogan & Lund, 2009 [5161]: Operculate chondrichthyan fishes with laterally compressed bodies entirely covered with a delicate, simple shagreen of denticular placoid scales with concentrations distal to dorsal and pelvic cartilages; pectoral fins situated at the nape of the neck, a single, low, aspinous dorsal fin, internally and externally homocercal tail (Fig. 10). Cranium comprised of separate ethmosphenoid, otic and occipital units, the latter derived from two transformed vertebral units. A chain of suprascapular cartilages (n = 3) provide a kinetic linkage between scapula and dorsal surface of otic cartilage, approximately at a postorbital level. Pectoral metapterygium moderately large, bearing about eight radials and axis of nine basals and eight radials. Pelvic girdle a single vertical curved cartilage supporting radials laterally on the ventral edge; girdles in close proximity in midline. Large delicate mesial palatal dentigerous plates, other buccal plates either sparse or absent; palatobuccal dentition of fine unicuspid teeth; enlarged upper parasymphysial and lower symphysial tooth whorls supported on separate labial cartilages; broad palatoquadrate with tall vertical pterygoid process articulating dorsally on otic moiety of neurocranium.

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