Double-helical macrostructure aids the passive movement of extinctive graptolites (Dicellograptus) revealed by CFD simulation

Bibliographic Details
Title: Double-helical macrostructure aids the passive movement of extinctive graptolites (Dicellograptus) revealed by CFD simulation
Authors: Shijia Gao, Jingqiang Tan, Wenhui Wang
Source: Swiss Journal of Palaeontology, Vol 144, Iss 1, Pp 1-15 (2025)
Publisher Information: SpringerOpen, 2025.
Publication Year: 2025
Collection: LCC:Paleontology
Subject Terms: Ordovician, Dicellograptus, CFD simulation, Hydrodynamics, Functional morphology, Fossil man. Human paleontology, GN282-286.7, Paleontology, QE701-760
More Details: Abstract Understanding how marine organisms move in the water column is critical for comprehending their palaeoecology and palaeobiogeography. However, interpreting the locomotion of extinct invertebrates can be problematic and difficult because of the lack of close modern analogues or preserved soft tissues. In this study, we chose a biostratigraphically important Ordovician graptolite taxon, Dicellograptus, and reconstructed three-dimensional (3D) models of it. By simulating their rotation patterns via computational fluid dynamics (CFD), we tested three prevailing locomotory hypotheses (ā€œVā€-shaped structure, double-helix structure or independently spiralling twin turbaria structure) for Dicellograptus. The simulated hydrodynamic properties (outer-wall pressure fields and velocity fields) suggest that a double-helical rotating locomotory pattern was the most likely for the Ordovician graptolite Dicellograptus because it would have conveyed better feeding efficiency and turbarium stability. Moreover, we analysed whether the evolution from the lineages Jiangxigraptus to Dicellograptus was influenced and selected for by hydrodynamics. The results revealed that the modification of the proximal pattern with a broader first pair of thecae in Dicellograptus than in Jiangxigraptus resulted in reduced rotational velocity and increased stability. This study highlights the close relationship between traditional paleontological analysis and modern computational methods and provides a more comprehensive understanding of the functional morphology of these ancient marine plankton.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1664-2376
1664-2384
Relation: https://doaj.org/toc/1664-2376; https://doaj.org/toc/1664-2384
DOI: 10.1186/s13358-025-00356-7
Access URL: https://doaj.org/article/5d4dc22ecaf74f719a3ed444d1cad347
Accession Number: edsdoj.5d4dc22ecaf74f719a3ed444d1cad347
Database: Directory of Open Access Journals
More Details
ISSN:16642376
16642384
DOI:10.1186/s13358-025-00356-7
Published in:Swiss Journal of Palaeontology
Language:English