There were three subfamilies known as of 1993 (Ritchie (1993): Liopterinae, Oberthuerellinae, and Mesocynipinae. Oberthuerellinae has a noticeable spine on the underside of the metafemur; Liopterinae has the metasomal petiole elongated; and the petiole of the Mesocynipinae is shorter than wide.
Some species are believed to be parasitic on wood-boring insects (Coleoptera: Buprestidae; Hymenoptera: Siricidae). There were 13 genera more than 143 species known worldwide as of 2011, but they are found primarily in tropical areas.
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Benoit, P.L.G. 1955. Les Liopteridae Oberthurellinae du Congo Belge. Revue de Zoologie et de Botanique Africaines 52: 283–293.
Liu, Z, Ronquist, F. & Nordlander, G. 2007. The cynipoid genus Paramblynotus: revision, phylogeny, and historical biogeography (Hymenoptera, Liopteridae). Bulletin of the American Museum of Natural History 304: 1-151.
Ritchie, A.J. 1993. Superfamily Cynipoidea (pp. 521-536). In: Goulet, H. & J. Huber (eds). Hymenoptera of the World: an identification guide to families. Research Branch, Agriculture Canada, Ottawa, Canada, 668 pp.
Ronquist, F. 1995 Phylogeny and classification of the Liopteridae, an archaic group of cynipoid wasps (Hymenoptera). Entomologica scandinavica, supplement 46: 1-74.
Ronquist, F. 1999. Phylogeny, classification and evolution of the Cynipoidea. Zoologica Scripta 28:139–164.