An abundant nautiloid collection (> 100 specimens) from the Late Permian Bellerophon Formation of the Dolomites, apparently the largest Late Permian nautiloid fauna from Tethys and certainly the most diverse nautiloid collection from the Bellerophon Formation, has enabled individual and intraspecific variability connected both with ontogenetic changes to be probed. The shell morphology is much affected by differing modes of preservation (shell, internal mould, external cast or composite mould) and diagenetic deformation. Five genera and eight species (six new) have been determined. The new species are Tainoceras balestense, T. malsineri, Foordiceras dolomiticum, Liroceras gardenese, Peripetoceras comploji and P. gigas. Emended diagnosis is presented for Tirolonautilus, represented by two previously known species: T. crux (STACHE) and T. sebedinus (STACHE). The generic position is discussed of two species from the Dolomites, earlier described but not found in the present collections, Tainionautilus? darini (CANEVA) and Metacoceras inaequiseptum MERLA.
Late Permian Nautiloids from the Bellerophon Formation of the Dolomites (Italy)
POSENATO, Renato
2007
Abstract
An abundant nautiloid collection (> 100 specimens) from the Late Permian Bellerophon Formation of the Dolomites, apparently the largest Late Permian nautiloid fauna from Tethys and certainly the most diverse nautiloid collection from the Bellerophon Formation, has enabled individual and intraspecific variability connected both with ontogenetic changes to be probed. The shell morphology is much affected by differing modes of preservation (shell, internal mould, external cast or composite mould) and diagenetic deformation. Five genera and eight species (six new) have been determined. The new species are Tainoceras balestense, T. malsineri, Foordiceras dolomiticum, Liroceras gardenese, Peripetoceras comploji and P. gigas. Emended diagnosis is presented for Tirolonautilus, represented by two previously known species: T. crux (STACHE) and T. sebedinus (STACHE). The generic position is discussed of two species from the Dolomites, earlier described but not found in the present collections, Tainionautilus? darini (CANEVA) and Metacoceras inaequiseptum MERLA.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
