Cypriniform Diversity
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Biodiversity of Cypriniform Fossils

Fossil Cypriniform Fish ToL Portal:

Notropis megalepis fossil scan

Chinese Cypriniform fossils

Ostariophysan phylogeny versus stratigraphy

It is generally accepted that geological age is correlated to some degree with primitiveness, or in other words, there is a correlation between stratigraphic and phylogenetic data (e.g., Huelsenbeck, 1994; Benton et al., 1999).  Thus, the question arises, what does the age of the fossil ostariophysans tell us about the phylogenetic position of the main lineages?   To test it, we can use the available accepted hypothesis of phylogenetic relationships of ostariophysans proposed by Fink and Fink (1996) and the information on the oldest fossil records gathered for this research.  Figure 4 shows us that Gonorynchiformes are basal ostariophysans and are known from the Early Cretaceous.  The arrangement of the otophysans members also tell us that there is disagreement between age of the oldest fossils and the phylogeny.  The Siluriformes and Characiformes, with a more advanced phylogenetic position, are older than Cypriniformes.  If the phylogenetic hypothesis is correct, then we should expect that Cypriniformes would have arisen in the Cretaceous.  This incompatibility demmonstrates that the fossil record of cypriniforms is incomplete and that we are missing information of older fossil forms.  This is a significant point justifying the need of more collecting in freshwater environments in different continents, especially in the Cretaceous strata.  (It is possible that some of the isolated teeth interpreted as pycnodontiforms are not actually these taxa but represent Cypriniformes!).  To our knowledge, histological studies to determine the presence of ganoine or enamel have never been done to clarify the structure of the teeth and their probable assignment. We will test these assignments in some relevant material from the Late Cretaceous - Tertiary boundary of India and of Spain; material is available to this project.)

Another significant aspect of this study that fossil taxa are uniquely qualified to aid us in our study relates to the question of whether or not members of Cypriniformes were ever in South America and Australia.  We will examine fossils that are possible cypriniform representatives recently known from South America.  Furthermore, a more comprehensive approach to addressing this question will include phylogenetic, distributional and stratigraphic information from both Recent and fossil taxa that, when combined, will permit us to examine the historical biogeography of these fishes at various levels and examine the likelihood that these fishes were ever on these continental land masses.
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Questions or comments? Contact Director, Dr. Richard Mayden

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