Apterurus Rafinesque, 1810: 48

Apterurus Rafinesque, 1810: 48 , 62 (type species Apterurus fabronii Rafinesque, 1810 ; by monotypy) Cephalopterus Risso, 1810: 14 (type species Raja giorna Lacepède, 1803 ; by subsequent designation)

Apturus Rafinesque, 1815: 93 (emended spelling for Apterurus Rafinesque, 1810 )

Cephaloptera Cuvier, 1816: 138 (type species Raja cephaloptera Bloch & Schneider, 1801 ; by absolute tautonymy)

Dicerobatus Blainville, 1816: 112 (type species Raia mobular Bonnaterre, 1788 View in CoL ; by monotypy)

Dicerobatis Blainville, 1825: 40 (type species R. mobular Bonnaterre, 1788 View in CoL ; unjustified emendation of Dicerobatus Blainville )

Manta Bancroft, 1829: 454 (type species Cephalopterus manta Bancroft, 1829 View in CoL ; by monotypy)

Cephalopteram Griffith & Smith, 1834: 617 (erroneous spelling for Cephaloptera Cuvier, 1816 )

Ceratoptera Müller & Henle, 1837: 118 (type species Cephaloptera giorna Lesueur, 1824 View in CoL ; by subsequent monotypy)

Brachioptilon Hamilton in Newman, 1849: 2358 (type species Brachioptilon hamiltoni Hamilton, 1849 View in CoL ; by monotypy)

Diabolicthys Holmes, 1856: 45 (type species Diabolicthys elliotti Holmes, 1856 ; by monotypy)

Deratoptera Krefft, 1868: 3 , 9, Fig. (considered a misspelling of Ceratoptera Müller & Henle, 1837 )

Ceratobatis Boulenger, 1897: 227 (type species Ceratobatis robertsii Boulenger, 1897 ; by monotypy)

Pterocephalus Swainson, 1838: 170 View in CoL , 174 (type species R. giorna Lacepède, 1803 View in CoL ; replacement name)

Pterocephala Swainson, 1839: 321 (alternative spelling of Pterocephalus Swainson, 1838 View in CoL )

Daemomanta Whitley, 1932: 327 (type species Ceratoptera alfredi Krefft, 1868 View in CoL ; by original designation)

Indomanta Whitley, 1936: 11 (type species Indomanta tombazii Whitley, 1936 ; by monotypy)

Definition: (Adapted from Bigelow & Schroeder, 1953). Medium to very large rays with a rhomboidal disc, much wider than long, depressed and relatively thick. Head broad, dorsally flattened, protruding forward anteriorly of eye level; prominent cephalic lobes extending forward on each side of head, widely separated, curving forward from front of head; eyes positioned laterally on head; spiracles subcircular to slit-like, located either dorsal or ventral to plane of pectoral disc; mouth very broad, nearly straight, located either terminally or subterminally on head; numerous minute teeth present in tooth bands in either both jaws, or only in the lower jaw. Tail long to relatively short, whip-like, usually less than width of disc; small dorsal fin present opposite pelvic-fin bases; a small, serrated stinging spine sometimes present. Skin either naked or rough with numerous small denticles. Gill arches with numerous gill plates (50 to at least 140); gill plates thin, membranous or somewhat horny with cartilaginous basal supports; outer edge of gill plates with lateral lobes that are either rounded and separated from those on adjacent plates, or rod-like and fused to those on adjacent plates.

Nomenclatural discussion: In addition to the generic synonyms listed above, Lacepède (1798) named the genus Aodon for Squalus massasa , Squalus kumal and Aodon cornu for species lacking teeth. Squalus massasa and S. kumal were named by Forsskål (1775) from the Red Sea, but no adequate description is available to allow for species determination. Squalus massasa is considered a problematic species that was described as having long pectoral fins but no teeth. Aodon cornu was an unneeded new name for Squalus edentulus Brünnich, 1768 , which equals M. mobular ( Bonnaterre, 1788) . Aodon has therefore been used for a Mobula species, predating Mobula Rafinesque, 1810 ; however, the type species for this genus was subsequently designated by Jordan & Evermann (1896) as S. massasa .

Remarks: Separation of the genera Manta and Mobula has long been upheld due to the striking feature of a terminal versus a subterminal mouth, respectively. However, the comprehensive genetic analyses undertaken in this study provide the strongest evidence to date that separation of these genera is not warranted. The species previously designated to Manta , M. alfredi and M. birostris are clearly nested within Mobula , forming a close relationship with M. mobular and perhaps M. tarapacana , based on independent analyses of both mitochondrial genomes ( Fig. 1 View Figure 1 ) and more than 1000 nuclear exons ( Fig. 2 View Figure 2 ). Although a terminal versus subterminal mouth is a strong character, the dorsal versus ventral position of the spiracle in mobulids is another significant character. Both M. alfredi and M. birostris have slit-like spiracles located dorsal to the plane of the pectoral fins similar to those of M. mobular and M. tarapacana , and different to the subcircular spiracles located ventral to the plane of the pectoral fins in the remaining smaller Mobula species. This morphological character, therefore, largely supports the finding based on analysis of the mitochondrial genomes that M. birostris and M. alfredi form a clade with M. mobular and M. tarapacana , to the exclusion of the smaller mobulid species ( Fig. 1 View Figure 1 ). Both M. alfredi and M. birostris are also inferred as sister to M. mobular based on the independent analysis of nuclear exon data ( Fig. 2 View Figure 2 ), providing further support that the genus Manta is invalid. It should be noted, however, that a slightly different topology that places M. tarapacana basal to all other mobulid species is consistently resolved by the nuclear analysis with strong support ( Fig. 2 View Figure 2 ). This highlights the importance of integrated approaches to resolving taxonomy and inferring phylogeny, using both molecular and morphological approaches in combination.