Triassic coleoid beaks and other structures from the Calcareous Alps revisitedShow others and affiliations
2022 (English)In: Acta Palaeontologica Polonica, ISSN 0567-7920, E-ISSN 1732-2421, Vol. 67, p. 655-666
Article in journal (Refereed) Published
Abstract [en]
We performed comprehensive study of seven Carnian, Late Triassic specimens of a coleoid cephalopod Phragmoteuthis bisinuata, on which Suess based his hypothesis on “beaks of P. bisinuata”. Using SEM/EDS, we found that “beaks of P. bisinuata” consist of a micro-granular carbonized matrix containing ~4–30 μm diameter and ~50–200 μm visible length, dense calcified bone-like micro-structures. This strongly suggests that these objects are vertebrate bone-inducing cartilages in which the matrix was post-mortem reworked by carbon-accumulating bacteria and substituted by nano-particles of carbon accumulated in micro-granules. Hence, the presumed “beaks of P. bisinuata” are cartilaginous remains of a prey, presumably juvenile fish. This data dismissed the entire hypothesis of Seuss. A small spatula-shape plate with a rachis-like process in an association with 10 or so imprints around (arm crown), found in front of a proostracum of P. bisinuata evidences an unknown Late Triassic juvenile teuthid which possessed a gladius resembling that of the early Permian Glochinomorpha stifeli. It inhabited the open sea area of the northwestern Tethys Ocean, and was, along with juvenile fishes, in the diet of P. bisinuata. The first identified Anisian (Middle Triassic) coleoid beak is represented by an isolated specimen from the Gardena Valley, NE Italy. It has a typical composition and morphology of coleoid upper beak: chitinous, wide-oval lateral walls, short wings, and pointed hook-like rostrum. This suggests similar upper beak structure in the Carnian P. bisinuata in which the lower beaks were apparently similar to that of the co-occurring Lunzoteuthis schindelbergensis and had a widely open outer lamella with posteriorly elongated paired wings joined into a pointed rostrum in the anterior portion.
Place, publisher, year, edition, pages
Warsaw: Polish Academy of Sciences , 2022. Vol. 67, p. 655-666
Keywords [en]
Cephalopoda, Coleoidea, Phragmoteuthis, beaks, vertebrate and invertebrate prey, Triassic, Alps
National Category
Other Earth Sciences
Research subject
The changing Earth
Identifiers
URN: urn:nbn:se:nrm:diva-4911DOI: 10.4202/app.00953.2021OAI: oai:DiVA.org:nrm-4911DiVA, id: diva2:1715969
Note
This study was carried outthanks to financial support of the Austrian and Swedish Academies of Sciences, Department of Geology and Paleontology of the Museum of Natural History in Vienna and the Society “Friends of the Museum of Natural History, Vienna”, Department of Palaeobiology of the Swedish Museum of Natural History, and Museo de Ghereina, Italy
2022-12-042022-12-042025-09-12Bibliographically approved