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Re: Dinosaur Diversity Analyzed
Interesting little paper from Mike Taylor (who gave a link for
downloading a pdf in his last posting), with nice graphics.
Repeatedly emphasizes that the statistics he gives should be
approached with caution for a whole lot of reasons.
Sampling bias an obvious one: the very large number of dinosaur taxa
known from the United Kingdom (about (guesing and doing mental
arithmetic) 1/700 of the Earth's land area), for xample, surely
reflects the long history of geology as a science there!
Are there any good ways to estimate sampling bias? Paticularly: any
ways, using available infformation, to estimate which parts of the
Mesozoic have been better-sampled than others? For instance...
Somewhere in the literature there must be a reasonably complete and
compact list of all the dinosaur fossil sites that have been worked
in the last century or so: are some ages much better represented than
others? This would give a very crude indication-- site briefly
surveyed by a government geologist when the country it is in was a
colony would be counted as equivalent (for sampling) to one of the
extraordinarily rich sites that have been extensively excavated over
decades, but I suspect getting a more refined measure of sampling out
of the published literature would be very difficult.
(I know attempts at estimating sampling bias have been made in
connection with the question of whether dinosaur diversity was
declining in the late Cretaceous...)
University of Melbourne