Terebratuloid and cancellothyridoid brachiopods from the South-Helvetic Lutetian (Eocene) of the Fäneren region (NE Switzerland) are described: Carneithyris subregularis (QUENSTEDT) and two forms of Terebratulina s.l. under open nomenclature. Several species of Alpine and non-Alpine origin, related to Carneithyris subregularis, like Terebratula kickxi GALEOTTI, Terebratula aequivalvis SCHAFHÄ UTL and Terebratula hilarionis DAVID-SON show characters, which compare well with Carneithyris subregularis. Two of them, T. aequivalvis and T. hilarionis, are assigned to the genus Carneithyris. The stratigraphy and lithology of the sediments in the study area are reassessed. Life habits and palaeoecology of the brachiopods are discussed. C. subregularis apparently was a free living brachiopod without attachment to the substrate, as indicated by massive accumulations of callosities in the posterior parts of the shell. The variability of the cardinal process, as seen in the studied Carneithyris group can be interpreted as a morphological element to enlarge the surface of attachment of strong diductor muscles in relation to the internal thickening of the individual.
Arzonella exotica n. g. n. sp., a new brachiopod of indeterminate systematic position from the Lower Liassic (Broccatello) of Arzo (Southern Alps of Switzerland): A short note HEINZ SULSER A new brachiopod from the Lower Liassic of Arzo 423 SUMMARY A new brachiopod, Arzonella exotica n. g. n. sp., from the Liassic (Broccatello) of Arzo in the Southern Alps of Switzerland was described. By the associated rhynchonellid brachiopod Sulcirostra alpina the stratigraphical stage could be specified as Sinemurian. Arzonella exotica is an unusual, probably conservative form. Its systematic position is not established yet. Possible relationships were discussed. ZUSAMMENFASSUNG Ein neuer Brachiopode, Arzonella exotica n. g. n. sp., aus dem Lias (Broccatello) von Arzo in den Südalpen der Schweiz wurde beschrieben. Durch den assoziierten rhynchonelliden Brachiopoden Sulcirostra alpina konnte die stratigraphische Stufe als Sinemurian präzisiert werden. Arzonella exotica ist eine ungewöhnliche, wahrscheinlich konservative Form. Die systematische Position ist noch nicht geklärt. Mögliche Beziehungen wurden diskutiert. Giorgio (since 2003 Unesco World Heritage, see Furrer 2003).The species described here occurs in a greyish block of limestone, lithologically comparable with the typical facies of
New brachiopods (Dimerelloidea, Rhynchonellida) from Lower Jurassic (?lower Hettangian) hemipelagic sediments of the Swiss National Park in south-eastern Engadine are described: Sulcirostra doesseggeri sp. nov. and Carapezzia engadinensis sp. nov. Sulcirostra doesseggeri is externally similar to S. fuggeri (FRAUSCHER 1883), a dubious species, that could not be included in a comparative study, because relevant samples no longer exist. A single specimen was tentatively assigned to Sulcirostra ?zitteli (BÖSE 1894) by comparison of its external morphology with S. zitteli from the type locality. The partly silicified brachiopods are associated with sponge spicules, radiolarians and crinoid ossicles. Macrofossils are rare: dictyid sponges, gastropods, bivalves, crustaceans, shark teeth and scales of an actinopterygian fish. The Lower Jurassic sediments (Alpisella beds, a basal member of the Allgäu Formation) preserving the brachiopods belong to the Ortler nappe (Upper Austroalpine nappes). The exact age of the Alpisella beds is not known, as index fossils are lacking. Their stratigraphic position above the Rhaetian Kössen Formation and below the ammonite-dated Trupchun beds suggests a very Early Jurassic, probably early Hettangian age for the new brachiopod fauna. The new species of Sulcirostra and Carapezzia are confined to a very small geographic area, a peculiarity also observed in other Early Jurassic dimerelloid brachiopods. These brachiopods presumably adapted to current-dominated submarine highs, where their shells could not accumulate, except when trapped in submarine cavities or re-deposited in submarine fans. Transport by turbidity currents is suggested for the Early Jurassic dimerelloids from the Engadine. Problems with the generic definition of Sulcirostra and the higher rank classification of Carapezzia are discussed.
ZUSAMMENFASSUNG
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