What is "trygonoptera"

Trygonoptera is a genus of round rays endemic to the waters around Australia. Müller and Henle defined Trygonoptera in 1841. It has often been considered synonymous with Urolophus, but this has been refuted by recent studies. Trygonoptera can be distinguished from Urolophus in that the outer rims of its nostrils are enlarged into broad, flattened lobes; the two also differ in aspects of the skeleton.