Diversification in Polypteriformes and Special Comparison With the Lepisosteiformes |
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Authors: | M Gayet F J Meunier & C Werner |
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Institution: | FRE 2158 CNRS, UFR Sciences de la Terre, UniversitéClaude Bernard-Lyon I, Franc;, UMR 8570 CNRS, Laboratoire d'Ichtyologie générale et appliquée, Muséum national d'Histoire naturelle, France;, FSP-Geosys, Technische Universita¨t Berlin, Berlin, Germany |
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Abstract: | Polypteriformes (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'. |
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Keywords: | palaeodiversification Polypteriformes Lepisosteiformes Pangaea Cretaceous-Recent key innovation |
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