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| Titel |
Experimental taphonomy and the anatomy and diversity of the earliest fossil
vertebrates (Chengjiang Biota, Cambrian, China) |
| VerfasserIn |
Mark Purnell, Sarah Gabbott, Duncan Murdock, Peiyun Cong |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133049
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| Publikation (Nr.) |
 EGU/EGU2016-13619.pdf |
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| Zusammenfassung |
| The oldest fossil vertebrates are from the Lower Cambrian Chengjiang biota of China, which
contains four genera of fish-like, primitive vertebrates: Haikouichthys, Myllokunmingia,
Zhongjianichthys and Zhongxiniscus. These fossils play key roles in calibrating molecular
clocks and informing our view of the anatomy of animals close to the origin of vertebrates,
potentially including transitional forms between vertebrates and their nearest relatives.
Despite the evident importance of these fossils, the degree to which taphonomic processes
have affected their anatomical completeness has not been investigated. For example, some
or all might have been affected by stemward slippage – the pattern observed in
experimental decay of non-biomineralised chordates in which preferential decay of
synapomorphies and retention of plesiomorphic characters would cause fossil taxa to
erroneously occupy more basal positions than they should. This hypothesis is based on
experimental data derived from decay of non-biomineralised chordates under laboratory
conditions. We have expanded this analysis to include a broader range of potentially
significant environmental variables; we have also compared and combined the results
of experiments from several taxa to identify general patterns of chordate decay.
Examination of the Chengjiang vertebrates in the light of these results demonstrates
that, contrary to some assertions, experimentally derived models of phylogenetic
bias are applicable to fossils. Anatomical and phylogenetic interpretations of early
vertebrates that do not take taphonomic biases into account risk overestimating
diversity and the evolutionary significance of differences between fossil specimens. |
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