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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