Author: Garrick, 1956
Diagnostic Features:
Anterior nasal flaps short, not expanded into barbels; snout moderately long, pointed and flattened, length about 2/5 head length and about 2/3 of distance from mouth to pectoral origins; gill openings moderately wide, last one slightly broader than first 4; lips thin, not fringed, pleated or suctorial; teeth strongly different in upper and lower jaws, uppers small, with very narrow, acute, erect cusps and no cusplets, not bladelike, lowers much larger, bladelike, interlocked, with a high broad, erect or semierect cusp and distal blade, edges not serrated; tooth rows 57/34. Both dorsal fins spineless; first dorsal somewhat posterior on back, origin well behind pectoral fins, insertion well anterior to pelvic origins but slightly closer to pelvic bases than to pectorals; second dorsal slightly larger than first but with base less than 1.5 times as long as first; origin of second dorsal fin over rear half of pelvic bases; pectoral fins with short, broadly rounded free rear tips and inner margins, not expanded and acute or lobate; caudal fin asymmetrical, not paddle-shaped, with a long upper lobe, short lower lobe, and strong subterminal notch. No precaudal pits, lateral or midventral keels on caudal peduncle. Dermal denticles with moderately high, narrow pedicels and broad, flat, leaf-shaped, tricusped and triridged crowns. Cloaca normal, not expanded as a luminous gland. Colour uniform dark brown, apparently without conspicuous fin markings.
Remarks:
This genus is very close to the genus Scymnodon, as suggested by the original placement of its single species. See Garrick (1956) for a detailed discussion of the characters and rationale for separating Scymnodalatias from other squaloid genera. In addition to lacking fin spines, this genus differs from Scymnodon in having the first dorsal fin slightly more posterior on the back. Prof J.A.F. Garrick (pers. comm.) has what apparently is a new species of Scymnodalatias, also from New Zealand waters.