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Pterosaurian biogeography (free pdf)



Ben Creisler
bcreisler@gmail.com

A new open-access paper:


Paul Upchurch, Brian Andres, Richard J. Butler & Paul M. Barrett (2014)
An analysis of pterosaurian biogeography: implications for the
evolutionary history and fossil record quality of the first flying
vertebrates.
Historical Biology (advance online publication)
DOI:10.1080/08912963.2014.939077
http://www.tandfonline.com/doi/full/10.1080/08912963.2014.939077#.U9Z2G_ldXTo

The biogeographical history of pterosaurs has received very little
treatment. Here, we present the first quantitative analysis of
pterosaurian biogeography based on an event-based parsimony method
(Treefitter). This approach was applied to a phylogenetic tree
comprising the relationships of 108 in-group pterosaurian taxa,
spanning the full range of this clade's stratigraphical and
geographical extent. The results indicate that there is no support for
the impact of vicariance or coherent dispersal on pterosaurian
distributions. However, this group does display greatly elevated
levels of sympatry. Although sampling biases and taxonomic problems
might have artificially elevated the occurrence of sympatry, we argue
that our results probably reflect a genuine biogeographical signal. We
propose a novel model to explain pterosaurian distributions:
pterosaurs underwent a series of ‘sweep-stakes’ dispersal events
(across oceanic barriers in most cases), resulting in the founding of
sympatric clusters of taxa. Examination of the spatiotemporal
distributions of pterosaurian occurrences indicates that their fossil
record is extremely patchy. Thus, while there is likely to be genuine
information on pterosaurian diversity and biogeographical patterns in
the current data-set, caution is required in its interpretation.