Were all trilobites fully marine? Trilobite expansion into brackish water during the early Palaeozoic
| Autor: | Beatriz G. Waisfeld, Ricardo A. Astini, N. Emilio Vaccari, Luis A. Buatois, M. Gabriela Mángano, Diego F. Muñoz |
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| Rok vydání: | 2021 |
| Předmět: |
010506 paleontology
Paleozoic Trace fossil 010502 geochemistry & geophysics 01 natural sciences General Biochemistry Genetics and Molecular Biology Paleontology Animals 14. Life underwater Ordovician radiation Arthropods Saline Waters 0105 earth and related environmental sciences General Environmental Science geography geography.geographical_feature_category General Immunology and Microbiology Brackish water biology Fossils Estuary General Medicine Euryhaline biology.organism_classification Tremadocian Trilobite Palaeobiology Estuaries General Agricultural and Biological Sciences Geology |
| Zdroj: | Proc Biol Sci |
| ISSN: | 1471-2954 0962-8452 |
| DOI: | 10.1098/rspb.2020.2263 |
| Popis: | Trilobites, key components of early Palaeozoic communities, are considered to have been invariably fully marine. Through the integration of ichnological, palaeobiological, and sedimentological datasets within a sequence-stratigraphical framework, we challenge this assumption. Here, we report uncontroversial trace and body fossil evidence of their presence in brackish-water settings. Our approach allows tracking of some trilobite groups foraying into tide-dominated estuaries. These trilobites were tolerant to salinity stress and able to make use of the ecological advantages offered by marginal-marine environments migrating up-estuary, following salt wedges either reflecting amphidromy or as euryhaline marine wanderers. Our data indicate two attempts of landward exploration via brackish water: phase 1 in which the outer portion of estuaries were colonized by olenids (Furongian–early late Tremadocian) and phase 2 involving exploration of the inner to middle estuarine zones by asaphids (Dapingian–Darriwilian). This study indicates that tolerance to salinity stress arose independently among different trilobite groups. |
| Databáze: | OpenAIRE |
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