Chthamalus nasus, Carriol, René-Pierre, 2008

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 : 36

Chthamalus nasus sp. nov.

Fig. 2 (9a–10)

Diagnosis: Scutum much longer than broad, apex with a prominent blunt point, tergal margin sinuous.

Etymology: Morphological, alluding to the nose like apex of the scutum ( nasus = nose in Latin).

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

Material: Holotype: MNHN A25744 left scutum. Paratype: MNHN A25745 right scutum.

Measurements: Holotype MNHN A25744: occludent margin 1.7 mm. Paratype MNHN A25745 : occludent margin 1.3 mm.

Description: Scutum triangular with basal margin nearly as long as tergal margin, apex with prominent blunt point; externally ornamented with fine growth ridges on lower part, corroded on upper part; articular ridge extending beyond tergal margin forming median prominence; articular furrow rather broad, not deep; pit for adductor muscle round, shallow; pit for depressor muscle lacking; internal surface with some blind tubes.

Affinities: The prominent, bluntly pointed apex of the scutum of C. nasus sp. nov. can be distinguished from all the others species of Chthamalus .

Figures

FIGURE 2. 1 – 8, Chthamalus robustus sp. nov., external and internal side of plates: 1 a, b, scutum, holotype MNHN A 25746; 2, fragment of scutum, paratype MNHN A 25747; 3 a, b, 4, terga, paratypes MNHN A 25748, MNHN A 25749; 5 a, b, rostrum, paratype MNHN A 25750; 6 a, b, lateral, paratype MNHN A 25751; 7 a, b, carina, paratype MNHN A 25752; 8 a, b, rostro-lateral, paratype MNHN A 25753. 9 – 10, Chthamalus nasus sp. nov., external and internal side of plates: 9 a, b, 10, scuta, holotype MNHN A 25744, paratype MNHN A 25745. 11, Balanus nodulus sp. nov., external and internal side of a plate: 11 a, b, lateral, holotype MNHN A 25755. 12 – 13, Balanus spongicola spongicola Brown, 1844, external and internal side of plates: 12, scutum, MNHN A 25756, 13 tergum, MNHN A 25757.