Were all trilobites fully marine? Trilobite expansion into brackish water during the early Palaeozoic.

ABSTRACT: 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 wate

SUBMITTER: Mangano MG 

PROVIDER: S-EPMC7893218 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature