Vertebrate(Lecture ppt) Ch 9-1

Vertebrate(Lecture ppt) Ch 9-1 - Eusthenopteron ( ) Nature...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Eusthenopteron 新新新 ( 新新新新 ) Nature The pectoral fin of Panderichthys and the origin of digitsatherine A. Boisvert 1 , Elga Mark-Kurik 2 & Per E. Ahlberg 1 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 1 interpreted digits as derivatives of fin radials, but during the 1990s the idea gained acceptance that digits are evolutionary novelties without direct equivalents in fish fin skeletons. This was partly based on developmental genetic data 2 , but also substantially on the pectoral fin skeleton of the elpistostegid (transitional fish/tetrapod) Panderichthys , which appeared to lack distal digit-like radials 3 . Here we present a CT scan study of an undisturbed pectoral fin of Panderichthys demonstrating that the plate-like
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 14

Vertebrate(Lecture ppt) Ch 9-1 - Eusthenopteron ( ) Nature...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online