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No Sternum for _Archaeopteryx_



Hi All -

I just received this today, but don't recall seeing it on the list (pardon if it's a repeat!):

Wellnhofer, P. & Tischlinger, H. 2004. Das "Brustbein" von Archaeopteryx bavarica Wellnhofer 1993 - eine Revision. Archaeopteryx, 22: 3-15.

The abstract is very long, so I won't retype it here, but the paper basically reports on attempts to x-ray and CT scan _A. bavarica_ to see the exact shape of the sternum, to no avail; subsequent preparation, however, under UV light, unearthed (ba-dum, chik!) the fact that it _isn't_ a sternum -- it's part of the coracoid to which the "sternum" was originally reported to abut against. Specifically, "During this preparation...it became obvious that the bone which hitherto had been identified as a part of the sternal plate pressed tightly against the left coracoid is in fact the medial part of this same coracoid." And you _know_ it must be true because they used the word "hitherto." Anyway, their ultimate conclusion is that, with this new prep, the previously incompletely known coracoid of _Archaeopteryx_ can now be described and is "in its general morphology...neither avian, i.e. long and pillar-like, nor theropodan, i.e. short and semicircular. Rather it is unique in being somewhat intermediate in its form and in extending in two planes." Probably not a surprise to anyone familiar with the already "intermediate" state of various other characteristics of _Archaeopteryx_, but I guess it means all the people who only see 1's and 0's can now remove the "1" from their coding for this character in _Archaeopteryx_, at least if you were basing that on this specimen!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and     dinogami@hotmail.com
http://cactus.dixie.edu/jharris/

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