The pectoral fin of Panderichthys and the origin of digits

@article{Boisvert2008ThePF,
  title={The pectoral fin of Panderichthys and the origin of digits},
  author={Catherine A. Boisvert and Elga Mark-Kurik and Per Erik Ahlberg},
  journal={Nature},
  year={2008},
  volume={456},
  pages={636-638}
}
One of the identifying characteristics of tetrapods (limbed vertebrates) is the presence of fingers and toes. Whereas the proximal part of the tetrapod limb skeleton can easily be homologized with the paired fin skeletons of sarcopterygian (lobe-finned) fish, there has been much debate about the origin of digits. Early hypotheses interpreted digits as derivatives of fin radials, but during the 1990s the idea gained acceptance that digits are evolutionary novelties without direct equivalents in… 
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  • J. Clack
  • Biology
    Evolution: Education and Outreach
  • 2009
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Study of modern vertebrates, especially the evolutionary developmental genetics of Hox genes, are beginning to provide clues to the origin of digits, and these include new tetrapod-like fish and very primitive tetrapods that help to resolve questions of the sequence of acquisition of Tetrapod characters.
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