This article follows Chan et al. (2021) and the World Register of Marine Species in placing Thecostraca as a class of
Crustacea and in the following classification of thecostracans down to the level of orders. Previously, Thecostraca was considered a subclass of
Maxillopoda. Significant changes in the organization of Cirripedia's orders, families, and genera were introduced in 2021 by Chan et al. and accepted by the World Register of Marine Species. Class
Thecostraca Gruvel, 1905 • Subclass
Ascothoracida Lacaze-Duthiers, 1880 • Order
Laurida Grygier, 1987 • Order
Dendrogastrida Grygier, 1987 • Subclass
Facetotecta Grygier, 1985 • Subclass
Cirripedia Burmeister, 1834 • Infraclass
Acrothoracica Gruvel, 1905 • Order
Lithoglyptida Kolbasov, Newman & Hoeg, 2009 • Order
Cryptophialida Kolbasov, Newman & Hoeg, 2009 • Infraclass
Rhizocephala Müller, 1862 • Infraclass
Thoracica Darwin, 1854 • Superorder
Phosphatothoracica Gale, 2019 (
paraphyletic) • Order
Eolepadomorpha Chan et al., 2021 • Order
Iblomorpha Buckeridge & Newman, 2006 • Superorder
Thoracicalcarea Gale, 2015 • Order
Calanticomorpha Chan et al., 2021 • Order
Brachylepadomorpha Withers, 1923 • Order
Archaeolepadomorpha Chan et al., 2021 • Order
Verrucomorpha Pilsbry, 1916 • Order
Scalpellomorpha Buckeridge & Newman, 2006 • Order
Pollicipedomorpha Chan et al., 2021 • Order
Balanomorpha Pilsbry, 1916 ==Phylogeny==