A systematic revision of Stramentum (Stramentum) pulchellum (G. B. SOWERBY JR., 1843) (Cirripedia, Thoracica, Stramentidae) from the Bohemian Cretaceous Basin, the Czech Republic
Abstract
The single species within the genus Stramentum LOGAN, 1897, Stramentum (Stramentum) pulchellum, from the Lower to Upper Turonian strata in the Bohemian Cretaceous Basin (BCB) is reviewed. Only seven specimens are known to date; one is housed at Krupka Museum (Teplice), the others are held in the palaeontological collections of the National Museum in Prague.
These specimens were first described in 1887 by Fritsch and Kafka, but have not received attention since. Despite the fact that stramentids are rare within the BCB, all individuals available are articulated and very well preserved and, without exception, belong to S. (S.) pulchellum.
The Krupka Museum specimen differs in the shape of both the scuta and the upper latera, but this is interpreted as a result of slight disarticulation. Varying numbers of peduncular scales amongst individuals are indicative of several age groups and small, juvenile stramentids occur as external moulds in one lot at the National Museum.
Most Czech stramentids have been found attached to shells of the ammonite genera Lewesiceras and Collignoniceras.