The taphonomic clock in fish otoliths

Author(s)
Konstantina Agiadi, Michele Azzarone, Quan Hua, Darrell S. Kaufman, Danae Thivaiou, Paolo G. Albano
Abstract

Paleobiological and paleoecological interpretations rely on constraining the temporal resolution of the fossil record. The taphonomic clock, that is, a correlation between the alteration of skeletal material and its age, is an approach for quantifying time-averaging scales. We test the taphonomic clock hypothesis for marine demersal and pelagic fish otoliths from a 10-40 m depth transect on the Mediterranean siliciclastic Israeli shelf by radiocarbon dating and taphonomic scoring. Otolith ages span the last ∼8000 yr, with considerable variation in median and range along the transect. Severely altered otoliths, contrary to pristine otoliths, are likely to be older than 1000 yr. For pelagic fish otoliths, at 30 m depth, taphonomic degradation correlates positively with postmortem age. In contrast, no correlation occurs for demersal fishes at 10 and 30 m depth, mostly because of the paucity of very young pristine (<150 yr) otoliths, possibly due to a drop in production over the last few centuries. Contrary to molluscan and brachiopod shells, young otoliths at these depths are little affected and do not show a broad spectrum of taphonomic damage, because those that derive from predation are excreted in calcium- and phosphate-rich feces forming an insoluble crystallic matrix that increases their preservation potential. At 40 m depth, all dated otoliths are very young but rather damaged because of locally chemically aggressive sediments, thus showing no correlation between taphonomic grade and postmortem age. Our results show that local conditions and the target species population dynamics must be considered when testing the taphonomic clock hypothesis.

Organisation(s)
Department of Palaeontology
External organisation(s)
Australian Nuclear Science and Technology Organisation (ANSTO), Northern Arizona University, National & Kapodistrian University of Athens, University of Vienna
Journal
Paleobiology
Volume
48
Pages
154-170
No. of pages
17
ISSN
0094-8373
Publication date
2021
Peer reviewed
Yes
Austrian Fields of Science 2012
105118 Palaeontology
Keywords
ASJC Scopus subject areas
General Agricultural and Biological Sciences, Ecology, Evolution, Behavior and Systematics, Palaeontology, Ecology
Portal url
https://ucrisportal.univie.ac.at/en/publications/c88efd31-c45b-4f33-b46d-14c536b14936