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Re: Mammal - Like - Reptiles ... info needed.



I have a computer reconstruction of Ctenospondylus casei on my website from
a 70% complete specimen I found a few years ago. We are preparing to cast
the bones this spring.

Jim Wyatt, C.E.O.
Fossilnet, Inc.

http://www.fossilnet.com
-----Original Message-----
From: Jonkeria@aol.com <Jonkeria@aol.com>
To: DaveH47@delphi.com <DaveH47@delphi.com>
Cc: dinosaur@usc.edu <dinosaur@usc.edu>
Date: Monday, February 23, 1998 11:03 PM
Subject: Re: Mammal - Like - Reptiles ... info needed.


>Dave, in a message dated 98-02-23 01:03:40 EST, wrote:
>
><< I would definitely recommend John McLoughlin's book _Synapsida_, which
is
> regretably out-of-print, but should be at a local library.>>
>
>There is of course _The Ecology and Biology of the Mammal-like Reptiles_
>edited by Nicholas Hotton III and published by Smithsonian Institution
Press,
>but it is hard to get and very expensive (and even now just a tad dated.).
>
>  <<I consider myself
> a Therapsid-advocate, and I too would like to know if there are any web
pages
> or other recent reference sources devoted to them.  I think the Therapsids
> have gotten short shrift to tell you the truth.  They may not be as
> imagination-capturing as the Dinosaurs, but they *are* our ancestors and
> deserve media attention.>>
>
>Oh, I think that they are certainly as imagination-capturing as the
dinosaurs
>(oops, shouldn't have said that. Forgive me, oh dinosaur list-folk!) And on
>therapsid web sites, currently being constructed is my web site devoted
>entirely to the nonmammalian Therapsida. When complete it will have pics,
>phylogenies, and a whole lot of info on the eotheriodonts, dinocephalians,
>anomodonts, and theriodonts.
>
><And while we are on the subject, what is the current status of the
> Dromasauria?
> Are they a distinct Therapsid suborder, or are they considered part of
>another
> group like the Dicynodonts?  I know not much is known about the
Dromasaurs,
> but I thought maybe someone had some new insights...>>
>
>They are, no, I should say were, a very problematic little group of
critters.
>The Dromasaurian Threesome--Galeops, Galepus, and Galechirus, were once
>thought to have split off from basal herbivorous therapsids before the
>dinocephalians (Romer). From time to time it was recognized that they
shared
>features with the dicynodonts and the venyukovioids, and because of their
>large eye sockets and small size were considered juveniles of another
animal.
>They have recently been reanalyzed and recognized as a paraphyletic
assemblage
>of animals becoming more and more dicynodontian. The taxa "Dromasauria" and
>"Venyukovioidea [=Venyukoviamorpha]" have been discarded as they are para
and
>polyphyletic (and good riddance. One has a spelling that constantly proves
to
>be confusing and the other is too often mistaken to be Dromaeosauria). The
>former members of all these groups are considered basal anomodonts, the
group
>including the dicynodonts. The finding of Patranomodon (a rather complete
>specimen which told much about "dromasaur" anatomy), the most primitive
>anomodont, has suggested that Galepus and Galechirus are at the most
primitive
>grade (and they may form a group with Patranomodon--it would be the
>Galechiridae), and it has been demonstrated that Galeops is actually a form
>more advanced than even the Russian Otsheria. Does that clear everything
up?
>
>These references deal with the dromasaur problem extensively:
>Brinkman, D. 1981. The structure and relationships of the dromasaurs
>(Reptilia: Therapsida). Breviora, Museum of Comparative Zoology. 465, 1-34.
>
>Rubidge, Bruce S. and James A. Hopson. 1990. A new anomodont therapsid from
>South Africa and its bearing on the ancestry of Dicynodontia. South African
>Journal of Science, 86:43-45.
>
>Rubidge, Bruce S. and James A. Hopson. 1996. A primitive anomodont
therapsid
>from the base of the  Beaufort Group (Upper Permian) of South Africa.
>Zoological Journal of the Linnaean Society. 117: 115-139.
>
>
>-Christian Kammerer