|
If you are seeing this message, you may be experiencing temporary network problems. Please wait a few minutes and refresh the page. If the problem persists, you may wish to report it to your local Network Manager.
It is also possible that your web browser is not configured or not able to display style sheets. In this case, although the visual presentation will be degraded, the site should continue to be functional. We recommend using the latest version of Microsoft or Mozilla web browser to help minimise these problems.
Wiley InterScience | ||||||||||
  PalaeontologyVolume 45 Issue 2, Pages 361 - 376 Published Online: 24 Nov 2003 © The Palaeontological Association, 2010
Abstract | Full Text: PDF (Size: 800K) | Related Articles | Citation Tracking  Diversification in Polypteriformes and Special Comparison With the Lepisosteiformes Copyright Blackwell Publishers Ltd KEYWORDS palaeodiversification • Polypteriformes • Lepisosteiformes • Pangaea • Cretaceous-Recent • key innovation ABSTRACTPolypteriformes (or Cladistia) and Lepisosteiformes (or Ginglymodi) are two groups of freshwater fishes with ganoid scales. The earliest fossil records of these taxa are Albian (Lepisosteiformes) and Cenomanian (Polypteriformes) respectively in Gondwana; they are still extant. The 'first' appearance of the two groups in the fossil record (explosive in polypteriforms, gradual in lepisosteiforms) as well as their evolutionary mode (diversification/disparity or replacement) is described in detail. The lepisosteiforms appear to show a rapid radiation of post-Palaeozoic clades immediately upon origination, while the polypteriforms represent a counter-example with their sudden diversification and their sudden acquisition of several 'key innovations'.
| 
| |||||||||
