Balanus aculeatus Carriol

Carriol, René-Pierre, Cahuzac, Bruno & Lesport, Jean-François, 2011, New species of Acasta and Balanus (Balanoidea: Acastinae, Balaninae) from the Early Miocene (Burdigalian) of the Aquitaine Basin, France, Zootaxa 3109, pp. 60-68 : 66

Balanus aculeatus Carriol sp. nov.

Fig. 2 E–H

Type locality. Saucats (Le Péloua), Département Gironde, Aquitaine Basin, southwest France.

Type stratum. Early Burdigalian, shell-rich, rusty, coarse carbonate sands, with rounded clasts of reefal corals.

Material examined. Holotype: no. 19-12-23 (Lesport Collection), a carina with a fragment of basis in connection attached.

Measurements. Holotype: mid-height of parietes 29.3 mm.

Diagnosis. Paries exteriorly with strong, tubular spines.

Description. Plate straight, relatively tall, folded under an angle of 60 degrees at sheath level. Paries outer surface brown, with fine growth ridges crossed by very fine longitudinal ridges in superior 3/4, and longitudinal rows of strong, tubular spines. Paries tubiferous with 1 row of tubes with transverse septa; primary longitudinal septa, 27 in number, with lateral denticules. Sheath with growth ridges, lacking longitudinal ribs, occupying more than upper 1/2 of interior of plate; lower edge of sheath free of shell wall, with deep cavity beneath. Alae not cleft, with summits almost horizontal. Radii with transverse teeth on sutural edge smooth (characteristic deduced from traces left by sutural edge of radii of carinolateral on paries). Basis flat, calcified, tubiferous, single layered; tubes small with transverse septa.

Etymology. Alluding to the calcareous spines of the paries.

Affinities. Balanus nodulus Carriol, 2008 is the only other balanine with calcareous projections. The new species differs from B. nodulus in having both the tubes of the parietes and of the basis with transverse septa and by the parietal projections, which are strong, tubular spines, rather than small protuberances.

Figures

FIGURE 2. A – D, Acasta martillacensis sp. nov., holotype (no. 85 – 12 – 68), level GA 39191, a shell (basis, plus wall plates) with right scutum which was inside of the shell: A, right side of shell; B, external side of basis; C – D, external and internal side of scutum. E – H, Balanus aculeatus sp. nov., holotype (no. 19 – 12 – 23), carina with a fragment of basis in connection: E, basis magnified showing septed tubes; F, external side; G, internal side; H, lateral view.