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Re: Anatomical terminology



At 11:39 PM +0100 3/14/01, David Marjanovic wrote:
----- Original Message -----
From: "Teoslola" <bkazmer39@yahoo.com>
To: <dinosaur@usc.edu>
Sent: Tuesday, March 13, 2001 10:51 AM
Subject: Re: Anatomical terminology


 In all the Human Anatomy, Osteology, and Anthrolpology
 classes I have taken (my minor) we have used these
 "new" terms for many years now (over 20 years!).
 By definition aren't all vertebrae dorsal? So we
 wouldn't call any vertebra 'dorsal' so just simply
 caudalmost or even distalmost is permissible.

Just to add to the confusion -- no. In mammals, such as humans, vertebrae are grouped as cervical (neck), thoracic (chest), lumbar, sacral and... however that fused remnant of the tail is called; in most other tetrapods, there is no difference between thoracic and lumbar vertebrae, so these are lumped as "back vertebrae" -- dorsal ones, and people didn't have enough fantasy to invent a second adjective for that. All dorsal vertebrae, however, are proximal by definition, so one has to use cranial and caudal (or anterior and posterior, the meanings of which are clear _in this case_).

Hope this helps more than it confuses...


David,

Excellent explanation and a nice post.

As in the rise of vertebrates to land and evolution ensued so has the change over time in the way things are described. The following citations are certainly not new, but the system you describe as it refers to tetrapods is much in evidence in these. For people who are curious enough to want to see this system used classically, I would recommend trying to find copies of the following:

Jarvik, E. 1977. The systematic position of acanthodian fishes. Linnean Society Symposium Series 4; pp: 199-225.

Jarvik, E. 1986. The origin of the Amphibia. In: Rocek, Z. (Ed.) Studies in herpetology. pp: 1-23.

Jarvik, E. 1968. Aspects of vertebrate phylogeny. In: Current problems of lower vertebrate phylogeny. Nobel Symposium, pp: 497-527.

Cheers,
MDW
--
                        =00=  =00=  =00=  =00=
                        Marilyn D. Wegweiser, Ph.D.
                Adjunct Curator of Vertebrate Paleontology
                     Cincinnati Natural History Museum

Assistant Professor of Geology
Department of Geology                   mdwegweiser@bsu.edu
Ball State University                   Office: 765-285-8268;765-285-8270
Muncie, Indiana 47306                   FAX:    765-285-8265