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

Autor: Mángano MG; Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada., Buatois LA; Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada., Waisfeld BG; Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sarsfield 1611, Ciudad Universitaria, Córdoba X5016CGA, Argentina.; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), Edificio CICTERRA, Av. Vélez Sársfield 1611, Ciudad Universitaria, Córdoba X5016CGA, Argentina., Muñoz DF; Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sarsfield 1611, Ciudad Universitaria, Córdoba X5016CGA, Argentina.; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), Edificio CICTERRA, Av. Vélez Sársfield 1611, Ciudad Universitaria, Córdoba X5016CGA, Argentina., Vaccari NE; Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sarsfield 1611, Ciudad Universitaria, Córdoba X5016CGA, Argentina.; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), Edificio CICTERRA, Av. Vélez Sársfield 1611, Ciudad Universitaria, Córdoba X5016CGA, Argentina.; Universidad Nacional de La Rioja, Av. Luis M. de la Fuente s/n, F5300 La Rioja, Argentina., Astini RA; Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sarsfield 1611, Ciudad Universitaria, Córdoba X5016CGA, Argentina.; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), Edificio CICTERRA, Av. Vélez Sársfield 1611, Ciudad Universitaria, Córdoba X5016CGA, Argentina.
Jazyk: angličtina
Zdroj: Proceedings. Biological sciences [Proc Biol Sci] 2021 Feb 10; Vol. 288 (1944), pp. 20202263. Date of Electronic Publication: 2021 Feb 03.
DOI: 10.1098/rspb.2020.2263
Abstrakt: 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: MEDLINE
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