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RE: 11th specimen of Archaeopteryx
- To: Don Ohmes <email@example.com>, Dinosaur Mailing List <firstname.lastname@example.org>
- Subject: RE: 11th specimen of Archaeopteryx
- From: Jaime Headden <email@example.com>
- Date: Mon, 31 Oct 2011 22:25:55 -0600
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Don Ohmes wrote:
<[A]re you saying that the foot of A. lithographica would have been unable to
grasp your wrist?>
Yes, he is.
All "Archie" specimens that show a reversed hallux, as of the Thermopolis
specimen, show such a "morphology" due to a loose first metatarsal. It is not
articulated. Articulation would, as some of the specimens show, that the
phalanx is oriented closer to the "heterodactyl" orientation than it is to the
"anisodactyl" orientation. Moreover, its position is too high and its length
too short to enable actual grasping of anything: the pdI-1/pdI-2u articulation
is not so close to the substrate on a static foot that the claw could have
encompassed a branch it could stand on.
Sadly, while widely cited and somewhat widely read, this mostly appears in
Kevin Middleton's PhD thesis:
Middleton, K. M. 2003. Morphology, evolution, and function of the avian hallux.
Ph.D. dissertation, Brown University, Providence, Rhode Island.
This has been variously presented at symposia, which has helped disseminate
the data, so the information is "known," even though its source remains
relatively unpublished (for the purposes of U. S.-based availability). It also
appears, although in somewhat muted form, in Middleton (2001), which is
http://www.brown.edu/Departments/EEB/EML/files/kevin_jmorph01.pdf . This work
sets down the firm basis of inferring hallucial orientation by the morphology
of MTI, which bears a "twist" on it as indicated by a ridge, or a J-shaped
form, both of which are absent in *Archaeopteryx lithographica* specimens.
This, coupled with MTI disarticulation in most "Archie" specimens, indicates
one cannot say that "Archie" was capable of grasping _anything_ with its first
PS: I restate my objection to using largely unpublished information to
support these hypostheses
Jaime A. Headden
The Bite Stuff (site v2)
"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion
> Date: Mon, 31 Oct 2011 23:24:17 -0400
> From: email@example.com
> To: firstname.lastname@example.org
> Subject: Re: 11th specimen of Archaeopteryx
> On 10/31/2011 10:50 PM, David Marjanovic wrote:
> > Still, their feet are better suited to this than Archie's or even
> > *Microraptor*'s.
> Wikipedia has an image of the "London Specimen" -- are you saying that
> the foot of A. lithographica would have been unable to grasp your wrist?
> Or walk on a horizontal branch the same diameter as your leg?