Article: New actinopterygian fish from the Namurian Manse Burn Formation of Bearsden, Scotland
Four new species of actinopterygians are described from the Manse Burn Formation (Namurian) of Bearsden, Glasgow, Scotland. Two fusiform species are members of, and a third is questionably assigned to, Mesopoma: M. carricki, M. ?smithsoni, and M. pancheni. A new gibbose species is assigned to a new genus, Frederichthys musadentatus. Mesopoma is reviewed and rediagnosed, and its relationships to Frederichthys are examined with regard to a recent analysis of early actinopterygian (palaeoniscid) phylogeny; Mesopoma is a member of a probably paraphyletic group within a polytomous stem-group actinopteran radiation. An alternative phylogeny places Mesopoma on the common stem-group of the Haplolepidae, Aeduellidae, and Redfieldiformes. Frederichthys is closely related to the platysomids. Otoliths preserved within the mesopomid material are described and compared with those of other osteichthyans; the presence of three pairs of otoliths as a teleostome characteristic is questioned.