Pollicipes rigida

Jagt, John W. M., Zonova, Tatiana D. & Jagt-Yazykova, Elena A., 2007, A review of the brachylepadomorph cirripede genus Pycnolepas, including the first record of an Early Cretaceous species from the Russian Far East *, Zootaxa 1545, pp. 33-47 : 41-42

Pycnolepas aff. rigida (J. de C. Sowerby, 1836)

( Fig. 3 )

Localities and horizon. Localities 901 and 1024-I, near Vassa (Vassinskaja protoka), southwest of Bogorodskoye, Khabarovsk region ( Fig. 2 ); middle Albian ( Sey et al., 2004: table 6), zone of Cleoniceras sp. and Inoceramus ex gr. anglicus Woods, 1911 . Associated faunal elements include the inoceramid bivalve I. udylensis Zonova, 1989 and ammonoids ( Beudanticeras sp., Marshallites sp.).

Material. Three right scuta (VSEGEI/ CNIGR Museum, nos 57/13062, 58/13062, 130/13062), one left scutum (VSEGEI/ CNIGR Museum, no. 128/13062) and a single, fragmentary carina (VSEGEI/ CNIGR Museum, no. 129/13062), collected in 1966 and 2000 by V.D. Ovchinnikov and L.P. Ejkhvald, respectively.

Description. Scuta are elongately triangular, strongly convex transversely, mainly in apical portion; apex strongly curved towards terga; basilateral portion slightly produced; occludent margin strongly convex; basal margin near-straight, oblique; upper part of tergo-lateral margin concave, lower part rounded, protuberant; apicobasal ridge conspicuous, of variable width, extending from apex to basilateral angle, with perpendicular sides and marked with transverse ridges of highly variable prominence; ornament on occludent and tergo-lateral sides of apicobasal ridge consisting of close-set transverse ridges, variable in number and spacing; no longitudinal ridges seen, but this may be preservation induced; inner side not exposed.

As preserved, VSEGEI/CNIGR Museum, no. 130/13062 ( Fig. 3 D), not illustrated by Sey et al. (2004), is c. 20 mm in length; maximum width (basal margin) is 9.5 mm, apicobasal ridge c. 2 mm at its widest point; ornament strongly abraded. VSEGEI/CNIGR Museum, no. 57/13062 ( Fig. 3 B) measures 15 mm in length, and 9 mm in width; basitergal angle broken; apparently damaged after publication by Sey et al. (2004) and glued; apicobasal ridge flattened, conspicuously wide, with prominent sides. VSEGEI/CNIGR Museum, no. 58/13062 ( Fig. 3 A) also has suffered extensive damage since it was illustrated by Sey et al. (2004: pl. 92, fig. 15a, b), the occludent portion is now missing; as preserved, it measures 13 mm in length and c. 10.5 mm in width, showing an abraded apicobasal ridge. VSEGEI/CNIGR Museum, no. 128/13062 ( Fig. 3 C) is the best preserved valve in the present lot; it measures 22 mm in length and c. 10 mm in width; apicobasal ridge well developed, 1 mm in width and divided into two by a shallow central furrow.

The carina (VSEGEI/CNIGR Museum, no. 129/13062; Fig. 3 E, not illustrated by Sey et al., 2004) is broken apically and basally; semicylindrical, moderately curved inwards, strongly convex transversely, yet not carinate, basal margin slightly concave centrally; ornament of irregularly spaced, raised and slightly undulating ridges; interspaces (near-) smooth. As preserved, it measures 15 mm in length (estimated to have been> 20 mm originally), with basal width of at least 6.5 mm.

No other capitular valves or imbricating plates known.

Figures

FIGURE 2. Map showing provenance area in the Khabarovsk region, Russian Far East (inset), and simplified map of the Amur River near Vassa and Irkutskoye, south of Bogorodskoye. Localities 901 and 1024 - I are in the same general area, near Vassa, referred to as Vassinskaja protoka.

FIGURE 3. Pycnolepas aff. rigida (J. de C. Sowerby, 1836), all capitular valves from localities 901 and 1024 - I, Vassinskaja protoka, southwest of Bogorodskoye, Khabarovsk region, Russian Far East. A, fragmentary right scutum (VSEGEI / CNIGR Museum, no. 58 / 13062), locality 901, leg. V. D. Ovchinnikov, 1966 (= Sey et al., 2004: pl. 92, fig. 15 a, b); B, fragmentary right scutum (VESGEI / CNIGR Museum, no. 57 / 13062), locality 901, leg. V. D. Ovchinnikov, 1966 (= Sey et al., 2004: pl. 92, fig. 14 a, b); C, left scutum (VSEGEI / CNIGR Museum, no. 128 / 13062), locality 1024 - I, leg. L. P. Ejkhvald, 2000 (= Sey et al., 2004: pl. 92, fig. 16); D, abraded right scutum (VSEGEI / CNIGR Museum, no. 130 / 13062), locality 1024 - I, leg. L. P. Ejkhvald, 2000; E, fragmentary carina (VSEGEI / CNIGR Museum, no. 129 / 13062), locality 1024 - I, leg. L. P. Ejkhvald, 2000. Scale bars equal 10 mm.