Rhynchobatus Müller & Henle, 1837

Last, Peter R., Séret, Bernard & Naylor, Gavin J. P., 2016, A new species of guitarfish, Rhinobatos borneensis sp. nov. with a redefinition of the family-level classification in the order Rhinopristiformes (Chondrichthyes: Batoidea), Zootaxa 4117 (4), pp. 451-475 : 471-472

Genus Rhynchobatus Müller & Henle, 1837

Type species. Rhinobatus laevis Bloch & Schneider, 1801 (by monotypy).

Description. Nostrils large, very elongate, length exceeding internasal distance, not widely separated; posterior aperture narrowly elongate and not or only partly covered by anterior nasal flap, oblique and strongly curved posteriorly, much larger than anterior aperture. Anterior nasal flaps bilobed, not fused to form a nasal curtain, small and short based (less than 1/2 nostril length); insertion on snout at or very close to nostril margin, well forward of middle of posterior aperture, very well anterior and well lateral to innermost corner of posterior aperture (insertions of flaps very widely separated, by much more than internasal distance); anterior aperture medium-sized, subtriangular, expanded horizontally, posteromedial edge formed by prominent outer lobe-like extension of anterior nasal flap (positioned anteriorly on nostril); inner lobe of anterior nasal flap very short-based and narrow with an oblique, weakly convex margin; posterior margin of anterior aperture bordered by slender posterolateral nasal flap; free lobe of posterolateral nasal flap extending posteromedially, but tip not reaching middle of posterior aperture of nostril; posterior nasal flap fold-like, narrower than posterolateral nasal flap, base relatively short (often obscure). Lower jaw undulate and strongly convex at symphysis; skin margin forming upper lip strongly concave; usually three short but deep grooves at its angle (one anteriorly, two posteriorly); weak oral groove extending from forward of upper jaw and joined loosely on chin amid ridges of corrugated skin.

Species. R. australiae Whitley, 1939 , R. djiddensis (Forsskål, 1775) , R. immaculatus Last, Ho & Chen, 2013 , R. laevis (Bloch & Schneider, 1801) , R. luebberti Ehrenbaum, 1915 , R. palpebratus Compagno & Last, 2008 , R. springeri Compagno & Last, 2010 .