Potamotrygonidae
River stingrays or freshwater stingrays are Neotropical freshwater fishes of the family Potamotrygonidae in the order Myliobatiformes , one of the four orders of batoids , cartilaginous fishes related to sharks . 
<triplet> family <subj> order <obj> part of <triplet> Potamotrygonidae <subj> Myliobatiformes <obj> parent taxon