Actinobalanus Moroni, 1967

Carriol, René-Pierre, 2008, New genus and new species of Cirripedia (Chthamalidae, Tetraclitidae, Archaeobalanidae and Balanidae) from the Middle Miocene of the faluns of Touraine (France), Zootaxa 1675, pp. 31-48 : 40

Genus Actinobalanus Moroni, 1967

Type species: Actinobalanus actinomorphus ( Moroni, 1952) by original designation.

Diagnosis (after Zullo & Perreault 1989): Parietes monolamellar, solid, smooth or costate; parietal ribs not denticulate; radii solid, narrow to broad, disparietal or paraparietal (fine striations present on sutural edges of A. dolosus Darwin, 1854 a); basis calcareous, tubiferous; interior of scutum and tergum usually rugose; scutal adductor ridge present; no callus between scutal adductor and articular ridges; scutal depressor muscle pit absent or small and deep, without crests; tergal spur narrow to broad, short, usually acuminate, basally rounded or subtruncate, with spur fasciole.

Remark: The Actinobalanus specimens, generally eroded, from Pauvrelay and Ferrière-Larçon consist of disarticulated capitular plates and dissociated opercular plates, of which the latter belong to A. bisulcatus ( Darwin, 1854a) and A. collinsi Zullo & Perreault, 1989 . In this condition, the specific assignment of the capitular plates cannot be established.

Discussion: Actinobalanus dolosus has been reported by Lecointre (1910) from the Middle Miocene of the faluns of Touraine. This record is based on three shells without opercular plates. Zullo & Perreault (1989) do not consider them valid, firstly because the specimens are unidentifiable without opercular plates, and secondly because they are considerably older than Darwin’s Middle-Upper Pliocene English records. Carriol (1992) agreed with this assessment. However, to be absolutely sure that these specimens do not belong to A. dolosus , it is necessary to check the lack of striations on the sutural edges of their radii. Lecointre’s published description gives no enlightenment on this point, because it simply comprises a translation of Darwin’s (1854a) description of some Middle-Upper Pliocene English specimens rather than a description of his new material. A re-examination and description of the material is required, although the present author has been unable to locate Lecointre’s material. Material subsequently sampled has yielded numerous opercular plates of A. collinsi and three of A. bisulcatus , but none of A. dolosus , and numerous capitular plates without striations on the sutural edges of the radii, which are not capitular plates of A. dolosus . If the specimens assigned by Lecointre to A. dolosus are Actinobalanus , they may be A. bisulcatus or A. collinsi . There does not appear to be any justification for maintaining A. dolosus in the cirripede fauna from the faluns of Touraine.