The British Silurian ostracod genus Octonaria Jones, 1887: its revision and phylogeny

Abstract. The ostracod genus Octonaria Jones, 1887 has been grossly misunderstood because of misleading illustrations of the type-species, O. octoformis Jones, 1887. The type species is considered to be the only member of the genus presently known. All other of the nearly four dozen species and varieties which have been placed in the genus are considered to be junior synonyms of O. octoformis or members of other genera. Octonaria is presently known only from late Wenlock to early Ludlow strata of the Welsh Borderland area. It was probably derived from a “Bairdiocypris” gotlandica – like ancestor and is ancestral to the Late Silurian – Early Devonian North American genus Thlipsorothella Lundin & Petersen, 1974.