Synonym: Orthacea Woodward and Schuchert 1852 [replaced name]
Parent taxon: Orthidina according to M. Liljeroth et al. 2017
See also Alikhova 1953, Benedetto 2003, Bruton et al. 1984, Cooper 1976, Hansen and Holmer 2011, Henningsmoen 1952, Hints 2010, Hints 2014, Jakobsen et al. 2014, Jin and Chatterton 1997, Mitchell 1977, Neuman 1964, Neuman and Bruton 1974, Opik 1934, Oraspold 1956, Oraspold 1959, Owen and Harper 1982, Paškevičius and Hints 2016, Phleger 1933, Popov et al. 2009, Potter 1990, Rubel 2011, Temple 1987, Williams et al. 2000, Wright 1982, Zhan and Jin 2005, Zhang 1989, Zuykov and Butts 2008 and Zuykov et al. 2008
Sister taxa: Enteletacea, Plectorthoidea, Protorthacea, Triplesiacea, Yeosinella
Subtaxa: Anomalorthidae Archaeorthidae Bajanorthis Bohemiellidae Cathaysiorthidae Dinorthidae Dolerorthidae Glyptorthidae Hesperonomiidae Hesperorthidae Lycophoriidae Malinella Nugnecella Orthidae Orthidiellidae Ottadalenites Plaesiomyidae Poramborthidae Productorthidae Skenidioidae Tarfayidae Toxorthidae Turarella Whittardiidae Zhejiangorthis
Ecology: stationary epifaunal suspension feeder