Virtual 3D modeling of the ammonoid conch to study its hydrostatic properties

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Daniel A. Morón-Alfonso - , Universidad de Buenos Aires (Author)
  • David J. Peterman - , Wright State University (Author)
  • Marcela Cichowolski - , Universidad de Buenos Aires (Author)
  • René Hoffmann - , Ruhr University Bochum (Author)
  • Robert E. Lemanis - , Multi-scale Analysis (Junior Research Group) (Author)

Abstract

Computed tomography has provided a wealth of biological data that now stands beside a vast, more traditional, morphometric database. By exploiting these two resources, we present a novel methodology to construct intricate, virtual cephalopod shells. As a case of study, we applied this method to Maorites seymourianus using data obtained from a previous work. For this purpose, evaluation of the conch geometry, and the definition of new parameters such as the segment width expansion rate (SWER), segment height expansion rate (SHER), the segment thickness expansion rate (STER), and three indices related, were introduced. The conch geometry of M. seymourianus follows a spiral that can be defined by a polynomial function. While similar to a logarithmic function, a polynomial fit is preferred because it reveals higher values of whorl expansion at the early ontogenetic phase and lower values reaching the adult body chamber. Results on the hydrostatic properties of the virtual models indicate that M. seymourianus would have a near neutral buoyancy, ranging from slightly positive to slightly negative, depending upon parameters that influence organismal mass. Positions of the center of mass and the center of buoyancy indicate that the studied species would have a relatively low hydrostatic stability, estimating a shell orientation of approximately 74-76° with respect to the vertical, with the aperture slightly inclined downwards relative to the horizontal plain.

Details

Original languageEnglish
Pages (from-to)467-480
Number of pages14
Journal Acta palaeontologica Polonica / Polska Akademia Nauk, Instytut Paleobiologii
Volume65
Issue number3
Publication statusPublished - 2021
Peer-reviewedYes

External IDs

ORCID /0000-0002-7259-3410/work/142252360

Keywords

ASJC Scopus subject areas

Keywords

  • 3D, Ammonoidea, Antarctica, Cephalopoda, Conch, Cretaceous, CT-scan, Morphometry, Virtual modeling

Library keywords