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Re: Moyer et al.: a good study, but not the last word
True, but as Holtz points out, bilateral symmetry (whether dorsal / ventral or
right / left) would be unlikely in the bacterial case.
Which reminds me -- does asymmetrical pigmentation exist in extant birds?
On Fri, Mar 7, 2014 9:18 AM EST Dan Chure wrote:
>And of course, some specimens might be bacteria and some might be
>melanosomes. This is not an all or nothing game.
>On 3/7/2014 5:50 AM, Thomas R. Holtz, Jr. wrote:
> Just a few notes to add to the comments on the new Moyer et al. paper on
> bacteria vs. melanosomes:
> There are some good observations in this. However, I think it is fair to say
> this is not the final word on the subject. I know that
> the UT Austin group that has previously published on melanosomes (including a
> former student) are hard at work on new studies which
> point to the paleo-examples as being actual melanosomes, and I await news
> from Jakob Vinther's lab.
> Regardless of the final truth, this is good for science: we have to test our
> Towards that end, a test I'd like to see. In crystal-level geochemical
> studies, it is standard operating procedure to publish
> "sample maps" of the crystal being probed, for verification and replication
> purposes. I do not recall seeing these for the previous
> melanosome studies. That might help to give confidence that a pattern of
> color was real, and thus probably original rather than
> postmortem bacterial growth. For instance: tracing down and across both left
> and right "wings" of Anchiornis and find the same
> distribution of supposed-white and supposed-black patterns would increase our
> confidence in their reality.
> Take care,
> Thomas R. Holtz, Jr.
> Email: email@example.com Phone: 301-405-4084
> Office: Centreville 1216
> Senior Lecturer, Vertebrate Paleontology
> Dept. of Geology, University of Maryland
> Fax: 301-314-9661
> Faculty Director, Science & Global Change Program, College Park Scholars
> Fax: 301-314-9843
> Mailing Address: Thomas R. Holtz, Jr.
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