Correlative tomography of exceptionally preserved Jurassic ammonite implies hyponome-propelled swimming
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
The extreme rarity of soft tissue preservation in ammonoids has meant there are open questions regarding fundamental aspects of their biology. We report an exceptionally preserved Middle Jurassic ammonite with unrivalled information on soft body organization interpreted through correlative neutron and X-ray tomography. 3D-imaging of muscles and organs of the body mass for the first time in this iconic fossil group provides key insights into functional morphology. We show that paired dorsal muscles withdrew the body into the shell, rather than acting with the funnel controlling propulsion as in Nautilus. This suggests a mobile, retractable body as a defence strategy and necessitates a distinct swimming mechanism of hyponome propulsion, a trait that we infer evolved early in the ammonoid–coleoid lineage.
Date Issued
2022-04-01
Date Acceptance
2021-10-04
Citation
Geology, 2022, 50 (4), pp.397-401
ISSN
0091-7613
Publisher
Geological Society of America
Start Page
397
End Page
401
Journal / Book Title
Geology
Volume
50
Issue
4
Copyright Statement
© 2022 Geological Society of America. For permission to copy, contact editing@geosociety.org
Subjects
Science & Technology
Physical Sciences
Geology
EVOLUTION
BEHAVIOR
NAUTILUS
TISSUE
ORIGIN
MODEL
Geochemistry & Geophysics
04 Earth Sciences
Publication Status
Published
Date Publish Online
2021-12-07