Genus Pristis Linck, 1790 Type species. Squalus pristis Linnaeus, 1758 (by monotypy, absolute tautonymy). Description. Nostrils very short and well separated, width less than or subequal to internasal distance; posterior aperture relatively short, broadly scythe-shaped, not markedly oblique to anterior aperture. Anterior nasal flaps distinctly bilobed, well developed, not fused to form a nasal curtain, rather short based with point of insertion often unclear (joined variably along nostril margin beyond midlength of posterior aperture); anterior aperture mediumsized, subcircular and well removed from lateral margin of head, posterior edge formed by well-developed, outer lobe-like extension of anterior nasal flap (positioned anteriorly and reaching across aperture); lateral and posterior margins of anterior aperture bordered by long, medium-width posterolateral nasal flap; posterolateral nasal flap extending posteromedially as a broad free lobe (almost to corner of posterior aperture of nostril), its tip recurved ventrally; posterior nasal flap variably developed, width often narrower than posterolateral nasal flap but base relatively long (about half of nostril width or more). Lower jaw straight to weakly convex; skin margin forming upper lip concave; lateral grooves short, few to many, directed anteriorly from mouth angle; no oral groove, weak groove sometimes on chin. Species. P. clavata Garman, 1906, P. pectinata Latham, 1794, P. pristis (Linnaeus, 1758), P. zijsron Bleeker, 1851.

Published as part of 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), pp. 451-475 in Zootaxa 4117 (4) on page 474, DOI: 10.11646/zootaxa.4117.4.1, http://zenodo.org/record/271659