The whiptail stingrays are a family, the Dasyatidae, of rays in the order Myliobatiformes. They are found worldwide in tropical to temperate marine waters, and a number of species have also penetrated into fresh water in North America, Africa, Asia, and Australia. Members of this family have flattened pectoral fin discs that range from oval to diamond-like in shape. Their common name comes from their whip-like tails, which are much longer than the disc and lack dorsal and caudal fins. All whiptail stingrays, except the porcupine ray (Urogymnus asperrimus), have one or more venomous stings near the base of the tail, which is used in defense. They range in size from 0.18 to 2.0 m (0.59 to 6.56 ft) or more across.
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^M Puckridge, PR Last, WT White and N Andreakis (2012) Phylogeography of the Indo-West Pacific maskrays (Dasyatidae, Neotrygon): a complex example of chondrichthyan radiation in the Cenozoic. Ecology and Evolution. DOI: 10.1002/ece3.448.
^ abLast, P.R., Naylor, G.J. & Manjaji-Matsumoto, B.M. (2016). "A revised classification of the family Dasyatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights". Zootaxa. 4139 (3): 345–368. doi:10.11646/zootaxa.4139.3.2.CS1 maint: Multiple names: authors list (link)