Peculiar tube-like bivalve with densely packed concave tabulae (Štramberk Limestone, Tithonian-Berriasian)
Abstract
he fossils described here are from the Tithonian-lower Berriasian Štramberk Limestone ofthe Czech Republic. The specimens consist of densely packed, straight to slightly curved short tubes.Each tube is composed of a single valve rather than two valves.
Some tubes show constrictions in thewall, generally on just one side. The lumen is almost completely filled with numerous densely packedslightly to strongly concave tabulae.
In some tubes, the tabulae form complete internal floors while inothers they connect to the wall with another tabula or seal the concavity in the underlying tabula. Thetubes somewhat resemble tubeworms, rudists, vermetids and calcareous algae.
However, based onmorphological similarities such as the tube-like morphology in longitudinal section and the shapes ofthe lamellae and tabulae, these tubes resemble oysters described from the Albian of Brazil. According-ly, we infer that the Štramberk tubes represent oysters or oyster-related bivalves.