The old and the new plankton: ecological replacement of associations of mollusc plankton and giant filter feeders after the Cretaceous?
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- Amane Tajika
- Paläontologisches Institut und Museum, Universität Zürich, Zürich, Switzerland
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- Alexander Nützel
- SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, Department of Earth and Environmental Sciences, Palaeontology & Geobiology, GeoBio-Center LMU, München, Germany
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- Christian Klug
- Paläontologisches Institut und Museum, Universität Zürich, Zürich, Switzerland
抄録
<jats:p>Owing to their great diversity and abundance, ammonites and belemnites represented key elements in Mesozoic food webs. Because of their extreme ontogenetic size increase by up to three orders of magnitude, their position in the food webs likely changed during ontogeny. Here, we reconstruct the number of eggs laid by large adult females of these cephalopods and discuss developmental shifts in their ecologic roles. Based on similarities in conch morphology, size, habitat and abundance, we suggest that similar niches occupied in the Cretaceous by juvenile ammonites and belemnites were vacated during the extinction and later partially filled by holoplanktonic gastropods. As primary consumers, these extinct cephalopod groups were important constituents of the plankton and a principal food source for planktivorous organisms. As victims or, respectively, profiteers of this case of ecological replacement, filter feeding chondrichthyans and cetaceans likely filled the niches formerly occupied by large pachycormid fishes during the Jurassic and Cretaceous.</jats:p>
収録刊行物
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- PeerJ
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PeerJ 6 e4219-, 2018-01-09
PeerJ