Genus Acroteriobatus Giltay, 1928

Type species. Rhinobatus (Syrrhina) annulatus Müller & Henle, 1841 (by subsequent designation). Elevated herein to genus rank from subgenus.

Description. Nostril distinctly longer than internasal distance; posterior aperture narrow, elongate, slightly oblique to anterior aperture. Anterior nasal flaps weakly bilobed, not fused to form a nasal curtain, very long based, inserted on snout well anterior (flaps almost joined) and well inward of innermost corner of posterior aperture; anterior aperture medium sized, suboval to subcircular, medial edge partly formed by long lobe-like extension of anterior nasal flap; inner part of anterior nasal flap relatively long with an almost horizontal, undulate margin; lateral and posterior margins of anterior aperture bordered by broad posterolateral nasal flap, extending posteromedially as free flap but tip falling well short on inner corner of nostril; posterior nasal flap very well developed, much broader than posterolateral nasal flap and base exceeding half nostril length Lower jaw horizontal; skin margin forming upper lip straight; single lateral groove at its angle; oral groove moderate, extending from beside jaws around chin.

Species. A. annulatus (Müller & Henle, 1841), A. blochii (Müller & Henle, 1841), A. leucospilus (Norman, 1926), A. ocellatus (Norman, 1926), A. salalah (Randall & Compagno, 1995), A. variegatus (Nair & Lal Mohan, 1973), A. zanzibarensis (Norman, 1926) .