Revision of the Balanid Barnacle Genus Concavus Newman, 1982, with the Description of a New Subfamily, Two New Genera, and Eight New Species

Abstract

The new balanid subfamily Concavinae is based on the genus Concavus Newman, 1982, and includes five genera and 29 species-group taxa. The subgenera Concavus, Tamiosoma Conrad, 1856 (senior synonym of Menesiniella Newman, 1982), and Arossia Newman, 1982, are raised to generic rank. Two new genera, Chesaconcavus (type species Balanus concavus chesapeakensis Pilsbry, 1916) and Paraconcavus (type species Balanus concavus pacificus Pilsbry, 1916), are proposed, based on fossil and extant species from North America. New species include Tamiosoma advena from the Pliocene of southern Florida, Chesaconcavus rossi and C. santamaria from the middle Miocene of Maryland, C. myosulcatus from the upper Miocene of Virginia, Arossia newmani from the middle Miocene of Maryland, A. rubra from the upper Miocene of central California, A. aurae from the lower Pliocene of North Carolina, and Paraconcavus margaritanus from the upper Miocene of southern California. Concavines, a predominantly Northern Hemisphere group, appear in the late Oligocene in North America and Europe, diversify and spread rapidly in the Neogene, and, with the exception of a few eastern Pacific relicts, become extinct before the late Pleistocene.