Megatrygon, Last, Peter R., Naylor, Gavin J. P. & Manjaji-Matsumoto, B. Mabel, 2016

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 : 356

Genus Megatrygon gen. nov.

Type species Trygon microps Annandale, 1908:393 ; newly proposed, monotypic.

Definition. Very large dasyatid (adults to 220 cm DW) characterised by the following: very robust, broad rhombic disc with pectoral-fin apex angular; snout broadly angular (~3 times combined orbit and spiracle length); eye very small and sunken; nasal curtain skirt shaped; mouth narrow, with 5 oral papillae; tail short (length subequal to DW), very broad-based and depressed anteriorly, very strongly tapered at caudal sting then becoming filamentous; pelvic fins large, protruding greatly beyond disc; dorsal fold forming a low ridge; ventral fold low with a very short base; caudal sting posterior on tail (distance from pectoral-fin insertion to caudal-sting base more than 3 times interspiracular width); skin densely covered with minute stellate denticles but denticle band absent; no median rows of thorns and scapular thorns absent; tail base and sides covered with thorny denticles; dorsal colour plain; ventral surface white, disc margin dark; tail plain, black distally; marine, Indo– West Pacific.

Etymology. Combination of the Greek mégas (great, large, mighty) and Greek trygon (stingray) with reference to the massive bulk of this gigantic stingray.

Species. M. microps (Annandale, 1908) .

Remarks. Newly erected, monotypic genus and formerly assigned to Dasyatis . The placement of Megatrygon microps in the family Dasyatidae is provisional as molecular data (see also Naylor et al., in press) suggest that it, along with the ‘amphi-American Himantura ’, are more closely related to the freshwater Neotropical stingrays ( Potamotrygonidae ) of South America. Further investigations are needed to determine the position of this species in the order Myliobatiformes , but it may belong in its own family.