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Re: THIS IS A DINOSAUR LIST!



>NON-DINOSAURIAN LITTLE BEASTIES (ARCHOSAURS NONETHELESS)
>
>With the intention of provoking some discussion (and so we don't have to read
>so much about astrophysics) I'd like to cast the following questions to all
list
>members. Can someone explain the priority argument over PODOPTERYX/
>SHAROVIPTERYX? David Peters recently mentioned this beastie, but I lost his
post
>on it. So, could he please re-iterate or, elsewise, could someone fwd me his
>post on it. This animal was presumably arboreal, but what other sensible
>speculations might be made on its behaviour? And, of course, how does it fit
>into the archosaur phylogenies? Likewise _Longisquama_? Friends and relatives?

Haven't a clue as to their phylogenetic positions - "Dinogeorge" Olshevsky
should have something to say about them, though... ;-)

And, the name "Podopteryx" was preoccupied by an insect (probably a beetle),
so they had to remname it.

>PRONUNCIATION OF WORDS WITH 'PTERYX'
>
>EVERYONE pronounces _Archaeopteryx_, _Podopteryx_, _Patagopteryx_,
>_Glossopteris_ etc etc WITH THE P. But, in 'The Flying Dinosaurs', Phil Currie
>expresses the opinion that the p should be silent, as it is in pterosaur. So
we
>should all be saying 'ar-kee-o-teris'. Thoughts?

Well, I'll never pronounce it that way.
>
>Could someone just remind me, which node is defined as the Ornithothoraces? 
>Hmmm, does the Titanosauria (Diplodocidae + Titanosauridae) remain tenable
since
>the discovery of the _Malawisaurus_ cranial material? 

Titanosauria as you describe it ("Diplodocidae" sensu lato [including
euhelopodids and dicraeosaurids] + "Titanosauridae" sensu lato) DOES seem to
be in trouble.  The two most sensible suggestions I've seen so far is 1)
Titanosauria (in the sense described below) is the sister taxon to all other
derived sauropods, with Camarasauridae as the sister group to Diplodocoidea
(the "Diplodocidae" sensu lato of above); or, 2) Diplodocoids are the sister
group to all other derived sauropods, with Brachiosauridae the sister taxon
to Ttianosauria.

Bonaparte, Salgado, and Coria have begun to use "Titanosauria" for
Titanosauridae + Andesauridae (=Andesaurus, Argentinosaurus, etc.).  I'm not
certain that the "andesaurids" are monophyletic, but they do seem to be the
sister group to the well-defined Titanosauridae.

>Did anyone ever sort out the 'Gorgosaur renaissance' problems (i.e. there were
>recent rumours that some albertosaur species were to be re-instated as
>_Gorgosaurus_. I posted this question a while back, but don't know if it was
>answered (due to mother-of-all file disasters mk 1).)

Okay, the problem goes basically like this:
Dale Russell synomymized Gorgosaurus and Albertosaurus in 1970, a practice
followed by most people since.  However, some of the "unifying" characters
(such as general gracility characters and a promaxillary fenestra visible in
lateral view) are *primitive* for Tyrannosauridae!  Therefore, it may be
that G. libratus and A. saurophagus do not form a monophyletic group outside
of all other tyrannosaurids, and instead that one (say Albertosaurus) is
closer to derived tyrant dinos than the other.  In this case, the generic
name "Gorgosaurus" should be restored to "libratus".  (And, of course,
"Gorgosaurus" is a much more evocative name than "Albertosaurus").

And, if anybody has resolved this in a technical publication, I haven't seen
it yet.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist
Dept. of Geology
University of Maryland
College Park, MD  20742
Email:Thomas_R_HOLTZ@umail.umd.edu (th81)
Fax: 301-314-9661
Phone:301-405-4084