The Trigonalidae (sometimes spelled Trigonalyidae but the former spelling has formal precedence) are one of the more unusual families of hymenopteran insects, of indeterminate affinity within the suborder Apocrita (though sometimes believed to be related to the Evanioidea), and presently placed in its own superfamily, Trigonaloidea. The Trigonalidae are divided into two subfamilies, Orthogonalinae and Trigonalinae. These wasps are extremely rare, but surprisingly diverse, with some 90 species in over 15 genera, and are known from all parts of the world.