Hypanus Rafinesque, 1818

Last, Peter R., Naylor, Gavin J. P. & Manjaji-Matsumoto, B. Mabel, 2016, A revised classification of the family Dasyatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights, Zootaxa 4139 (3), pp. 345-368 : 355-356

Genus Hypanus Rafinesque, 1818

Hypanus Rafinesque, 1818:272 . Type species Raja say Lesueur, 1817 ( Eschmeyer et al., 2016) .

Definition. Mixed group of small to very large dasyatids (adults 31–198 cm DW) characterised by the following: depressed to robust, weakly rhombic to rhombic disc with pectoral-fin apex narrowly angular to broadly rounded; snout obtuse to pointed and short to elongate (1–3 times combined orbit and spiracle length); eye typically large and protruding slightly (small and sunken in H. guttata ); nasal curtain skirt shaped or bilobed; mouth narrow to broad, with 3–5 oral papillae (typically with 3 centrally); tail short to very long and whip-like or filamentous distally (length 1.3–3 times DW), its base typically depressed oval and narrow to broad; pelvic fins medium-sized, protruding slightly to well beyond disc; dorsal fold variably developed, prominent, reduced to form a ridge, or absent; ventral fold low to rather deep with a short to long base; caudal sting close to tail base (distance from pectoral-fin insertion to caudal-sting base 2.1–2.6 times interspiracular width); median thorns on disc in a distinct row; denticle band typically very small or absent (well-defined in H. guttata ); skin smooth or with a patchy coverage of denticles (rough in H. rudis ); scapular thorns present, small, 1–2 or in a short row; median thorns on tail weak or continuous with median thorn row on disc, sometimes absent; remaining tail smooth or covered with fine denticles; dorsal coloration plain; ventral surface white, disc margin dark or reddish; tail plain coloured or dorsal surface darker than ventral surface; marine, Atlantic and Eastern Pacific.

Species. H. americanus (Hildebrand & Schroeder, 1928) , H. dipterurus ( Jordan & Gilbert, 1880), H. guttatus (Bloch & Schneider, 1801) , H. longus (Garman, 1880) , H. marianae (Gomes, Rosa & Gadig, 2000) , H. rudis (Günther, 1870) , H. sabinus (Lesueur, 1824) , and H. say (Lesueur, 1817) .

Remarks. Resurrected genus, formerly considered a junior synonym of Dasyatis ( Kottelat, 2013) , now provisionally consists of eight somewhat morphologically heterogeneous species. Six of these species cluster together based on molecular data (see Fig. 1), but provisional placement of H. marianae and H. rudis still needs to be confirmed when tissues become available.