Conodonts in Silurian hypersaline environments: Specialized and unexpectedly diverse

Autor(en)
Emilia Jarochowska, Viive Viive Viira, Rein Einasto, Rafal Nawrot, Oskar Bremer, Peep Männik, Axel Munnecke
Abstrakt

Hypersaline environments are commonly assumed to be barren of metazoans and therefore are avoided by paleontologists, yet a number of early Paleozoic jawless vertebrate groups specialized to live in such settings. Sampling bias against restricted settings resulted in substantial underestimation of their diversity. Rare studies venturing into such environments yielded multiple new species of conodonts, suggesting that the diversity and habitat range of these hyperdiverse predators of the early oceans are equally underestimated. We describe here autochthonous conodont fauna from evaporite-bearing horizons from the middle Silurian of Estonia that provide evidence for efficient osmoregulation in this group. Based on a global compilation of coeval conodont assemblages, we show that marginal-marine, periodically emergent environments were characterized by higher conodont diversity than open-marine shallow settings. This diversity is due to a high number of species occurring in these environments only. The high degree of specialization is also reflected by the highest within-habitat variability (β diversity) in marginal settings. Most conodont species had narrow environmental niches and, unlike in marine invertebrates, extreme environments were inhabited by the most specialized taxa. Such environments represent a large proportion of early Paleozoic tropical epicratonic basins. Our analysis allows quantification of the degree to which mid-Silurian conodont diversity is underestimated as a result of sampling bias against marginal-marine settings.

Organisation(en)
Institut für Paläontologie
Externe Organisation(en)
Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Tallinn University of Technology, Tallinn University of Applied Sciences, Uppsala University
Journal
Geology
Band
45
Seiten
3-6
Anzahl der Seiten
4
ISSN
0091-7613
DOI
https://doi.org/10.1130/G38492.1
Publikationsdatum
2017
Peer-reviewed
Ja
ÖFOS 2012
106003 Biodiversitätsforschung, 106047 Tierökologie, 105118 Paläontologie
Schlagwörter
ASJC Scopus Sachgebiete
Geology
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/819b4ce8-1632-4ced-928f-0b7261bcc1a7