Devonian brachiopods 20. paleo ecology of fixed sessile articulate brachiopods from the rhenish mountains central europe
Struve, W.
Senckenbergiana Lethaea 60(4-6): 399-434
1980
Accession: 005139333
Qualitative and quantitative results of a paleoecologic study on cemented (fixed sessile) Strophomenida, Davidsonia Bouchard-Chantereaux 1849, Auchmerella Struve 1964 and Schuchertellopsis (Krejcigrafella) Struve 1978, and Spiriferida including ADAPTATRYPA heckeri gen. et sp. nov. are recorded and interpreted. The peculiar orientation of these brachiopods was not caused by rheotropism as formerly concluded from shells occurring only on fragmentary substrate slabs. More completely preserved substrate specimens show concentric and radial arrangement of the cemented brachiopods which is essentially a slopelet line docking. The larval to brephic individuals attached themselves with their (straight) cardinal margins in the direction of the strike line of the slope of minute structural-morphological details or of the (generally coarser) concentric growth lines or growth bulges of the calcareous substrate skeleton, thus obtaining shelter and enabling their brachial (dorsal) valves to articulate easily. By early cementation, this peculiar orientation is retained; its origin is obscured because of the small dimensions of the docking slopes as compared to the size of the adult brachiopods. It is unknown whether a still unidentified articulate brachiopod shell was fixed accidentally to a slab of tabulate or stromatoporoid limestone or has cemented itself to the substrate. The life habit of Kerpina Struve 1961 is noted.