Particles cheetah3d7/26/2023 100-Million-year dynasty of giant planktivorous bony fishes in the Mesozoic seas. Cambrian pelagic ecosystems seem to have been more modern than previously believed.įriedman, M. The presence of nektonic suspension feeders in the Early Cambrian, together with evidence for a diverse pelagic community containing phytoplankton 7, 8 and mesozooplankton 7, 9, 10, indicate the existence of a complex pelagic ecosystem 11 supported by high primary productivity and nutrient flux 12, 13. Our observations demonstrate that large, nektonic suspension feeders first evolved during the Cambrian explosion, as part of an adaptive radiation of anomalocarids. borealis was a microphagous suspension feeder, using its appendages for sweep-net capture of food items down to 0.5 mm, within the size range of mesozooplankton such as copepods. The appendage bears long, slender and equally spaced ventral spines furnished with dense rows of long and fine auxiliary spines. Here we describe new material from Tamisiocaris borealis 6, an anomalocarid from the Early Cambrian (Series 2) Sirius Passet Fauna of North Greenland, and propose that its frontal appendage is specialized for suspension feeding. Anomalocarids, a group of stem arthropods that were the largest nektonic animals of the Cambrian and Ordovician periods, are generally thought to have been apex predators 3, 4, 5. However, animals occupying this niche have not been identified from the early Palaeozoic era. Large, actively swimming suspension feeders evolved several times in Earth’s history, arising independently from groups as diverse as sharks, rays and stem teleost fishes 1, and in mysticete whales 2.
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