Arcoscalpellum maximum (J. DE C. SOWERBY , 1829)

Kočí, Tomáš, Veselská, Martina Kočová & Jagt, John W. M., 2014, Barnacles (Crustacea, Cirripedia, Thoracica) From The Bohemian Cretaceous Basin Described By Fritsch And Kafka (1887), With The Exclusion Of The Family Stramentidae, Acta Musei Nationalis Pragae Series B (Acta Mus. Nat. Prag.) 70 (3 - 4), pp. 223-234 : 226-227

Arcoscalpellum maximum (J. DE C. SOWERBY, 1829)

Pl. 2, figs. 5–7

1829 Pollicipes maximus J. DE C. SOWERBY, p. 222, pl. 606, figs. 4, 6 (non figs. 3, 5).

1885 Scalpellum maximum (SOWERBY) : Kafka, p. 12, pl. 1, fig. Aa-c (non fig. 5B, C).

1886 Scalpellum maximum, var. bohemica KAFKA : Kafka, p. 564, pl. 1, fig. A (non fig. B, C).

1887 Scalpellum maximum, var. bohemica KAFKA : Fritsch and Kafka, p. 6, fig. 7a (non fig. 7b, c).

1893 Scalpellum maximum (SOWERBY) : Fritsch, p. 109, text-fig. 141 (incl. var. bohemica ).

1935 Scalpellum (Arcoscalpellum) maximum (SOWERBY) : Withers, p. 239, pl. 29, figs. 2-10; pl. 30, figs. 1–12; pl. 31, figs. 1–19.

M a t e r i a l. The lectotype carina of var. bohemicum, NM O 4022, is from Holice. Another specimen from Kunětická Hora was collected by Jan Jiljí Jahn (see Fritsch and Kafka, 1887, p. 6).

D e s c r i p t i o n. Carina with moderately to strongly convex tectum and moderately transversely arched, subcarinated and with prominent distinct narrow ridge on both sides; ridges separate tectum from parietes; parietes narrow, equalling about half tectal width, inclined outwards and sligthly concave; intraparietes slightly wider than the entire side of the valve side, set slightly inwards; intraparietes divided from parietes by strong distinctly rounded ridge; tectum length ranging from five to three times its width and moderately bowed inwards; wall very thin and widening gradually from apex; depth of valve approximately half width of tectum; basal margin acutely angular and inner margin almost straight.

R e m a r k s. It is interesting to note that all illustrations in the papers listed above (synonymy) are the same and all repeat the incorrect identification, as outlined by Withers (1935, p. 243). Arcoscalpellum angustatum (see above) develops only very fine apicobasal lines on the tectum and the carina is of smaller size.

O c c u r r e n c e (B C B). Holice.

O v e r a l l r a n g e. Lower Santonian – Upper Maastrichtian.