首页    期刊浏览 2024年09月18日 星期三
登录注册

文章基本信息

  • 标题:Triassic coleoid beaks and other structures from the Calcareous Alps revisited
  • 本地全文:下载
  • 作者:LARISA A. DOGUZHAEVA ; HERBERT SUMMESBERGER ; FRANZ BRANDSTAETTER
  • 期刊名称:Acta Palaeontologica Polonica
  • 印刷版ISSN:0567-7920
  • 电子版ISSN:1732-2421
  • 出版年度:2022
  • 卷号:67
  • 期号:3
  • 页码:655-666
  • DOI:10.4202/app.00953.2021
  • 语种:English
  • 出版社:Institute of Paleobiology PAS
  • 摘要: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.
国家哲学社会科学文献中心版权所有