Actinobalanus collinsi Zullo & Perreault, 1989

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 : 41-42

Actinobalanus collinsi Zullo & Perreault, 1989

Fig. 3 (1–2)

Actinobalanus collinsi Zullo & Perreault, 1989: 6 –8; pl. 1, figs 5–7; pl. 2; pl. 3, figs 1–4.

Type locality: Borgerhout (Berchem Formation, Edegem sands, Metro works spoil heaps) Antwerp, Belgium.

Occurrence: Ferrière-Larçon and Pauvrelay (Paulmy commune), Indre-et-Loire, France, faluns of Middle Miocene age.

Material: MNHN A24750: left scutum. MNHN A24751: right tergum.

In addition to the figured specimens, numerous unregistered opercular plates have been observed.

Measurements: MNHN A24750: occludent margin 3.2 mm, tergal margin 1.8 mm, basal margin 2.2 mm. MNHN A24751: scutal margin 2.5 mm, basal margin 2.5 mm.

Diagnosis (after Zullo & Perreault, 1989): Parietes usually coarsely costate; radii narrow, disparietal; scutum thick, without external radial ornament; scutal adductor ridge short, prominent, centrally located; scutal articular ridge extending well beyond tergal margin; tergum thick, narrow, with straight scutal margin produced into broad shelf; tergal spur short, acuminate, occupying less than one-third width of basal margin; juncture of tergal spur with carinal side of basal margin arcuate.

Remarks: The capitular plates of A. collinsi cannot be distinguished from those of A. bisulcatus . However, the opercular plates conform to the diagnosis.

Stratigraphic and geographic range: Lower Miocene, Belgium (known only from the type locality); Middle Miocene, France (faluns of Touraine).

The record of A. collinsi from the Middle Miocene of France extends the stratigraphic range and the geographic distribution of this species, which was previously known only in the Lower Miocene of Belgium.

Figures

FIGURE 3. 1 – 2, Actinobalanus collinsi Zullo & Perreault, 1989, external and internal side of plates: 1, scutum, MNHN A 24750; 2, tergum, MNHN A 24751. 3 – 7, Acasta vesiculosa sp. nov., external and internal side of plates: 3 a, b, carinolateral, paratype MNHN A 24753; 4, carina with broken sheath showing calcareous vesicles, holotype MNHN A 24752; 5, carino-lateral, paratype MNHN A 24755; 6, lateral, paratype MNHN A 24754. 7, Actinobalanus bisulcatus (Darwin, 1854 a), external side of a scutum, MNHN A 24749. 8, Tesseropora dumortieri (Fischer, 1866), internal side of a scutum MNHN A 24748. 9 – 10, Chthamalus grazianii sp. nov.: 9, magnified part showing protuberances on the external side of a rostro-lateral, paratype MNHN A 25741; 10, lateral showing punctuations on the internal side, paratype MNHN A 25742.