Revision of the Mesozoic freshwater fish clade Archaeomaenidae

Archaeomaenidae is a clade of Mesozoic freshwater fishes that includes the Australian species <i>Archaeomaene tenuis</i>, <i>Madariscus robustus</i> and <i>Wadeichthys oxyops</i>, the Antarctic <i>Oreochima ellioti</i>, the Chinese <i>Zaxilepis qinglongensis</i>, and the Mongolian <i>Gurvanichthys mongoliensis</i>. A comprehensive redescription of the genus <i>Archaeomaene</i> demonstrates that <i>Madariscus robustus</i> is a junior synonym of <i>Archaeomaene tenuis</i>, and thus constitutes an ontogenetic body-size series. A detailed revision of <i>W. oxyops</i> and <i>O. ellioti</i> also confirms their phylogenetic placements within Archaeomaenidae. Furthermore, the incompletely documented taxa <i>Z. qinglongensis</i> and <i>G. mongoliensis</i> are recognized as archaeomaenids. Archaeomaenidae therefore comprises a geographically widely distributed radiation of stem teleosts or teleosteomorphs that is closely related to the archetypal Eurasian clade Pholidophoridae. <i>Lynne Bean [[e-mail]] Research School of Earth Sciences, Australian National University, 142 Mills Road, Acton, ACT 2601, Australia.</i>