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Re: Waimanu & avian evolution (comments)
So, I have few comments/questions for all you list-members now that I
have read through the Slack et al. Waimanu paper. The real meat of the
manuscript is the date calibration and phylogenetic hypotheses, but at
the moment I want to draw attention to a few of the ideas raised by
their discussion of neornithine/pterosaur/archaic bird competition.
1) Is their method of estimating 'decline' a good one? The authors
looked at character evolution (body size) in pterosaurs, but the real
emphasis seems to be on apparent species diversity. However, this is
not an evenly applicable measure. Due to locomotor differences, it
should be expected that pterosaur species diversity would be low
compared to most bird groups (seabirds possible excepted), but may
still have been represented disproportionately in biomass or geographic
range. Any thoughts?
2) The authors make at least one comment about the possible impact of
early Falconiforms (which they have placed in the Cretaceous in this
analysis...I find that dubious for reasons that can be discussed
later). Even if the authors are correct about this ancient origin of
Falconiforms, is there any good reason to assume that the early forms
were already raptorial?
Of course, I would also love to hear everyone's thoughts regarding the
dated tree itself, which is ultimately the most important part of the
paper.
Cheers,
--Mike H.
On Friday, May 12, 2006, at 12:02 PM, Tim Williams wrote:
This was discussed earlier on this list, but this is the official
paper...
Kerryn E. Slack, Craig M. Jones, Tatsuro Ando, G. L. (Abby) Harrison,
R. Ewan Fordyce, Ulfur Arnason and David Penny (2006) Early Penguin
Fossils, Plus Mitochondrial Genomes, Calibrate Avian Evolution.
Molecular Biology and Evolution 23: 1144-1155