Re: Re: Aquatic dinosaurs

[Thomas_R_HOLTZ@umail.umd.edu (th81)]

George Olshevsky wrote:

>... the clade Dinosauria contains the clade Aves (as far as we
>know), but since in paleontology we are more accustomed to dealing with
>non-avian dinosaurs, we should consider attaching a formal name to the clade
>Dinosauria minus Aves, if only to avoid repeating the cumbersome term
>"non-avian dinosaurs." I'd like to suggest Eudinosauria ("good dinosaurs")
>for the name of this parataxon.

Unfortunately, "Eudinosauria" has already been employed by Novas (c. 1990)
for "Saurischia plus Ornithischia", or in other words, just Dinosauria.  (At
the time, Novas, and most everyone else, thought Herrerasauridae was outside
the "Saurischia plus Ornithischia" clade).

>Unfortunately, I use the name Aves for all dinosaurs closer to _Megalosaurus_
>than to _Iguanodon_ (after all, the birds came first)

Except that Saurischia is already the name employed for this clade.

>What we really need is an organization similar to the ICZN (if not identical
>with it) to codify and prioritize definitions of clades and so forth at
>levels above those of the family, so we can dispense with this nonsense about
>"my system" versus "their system," etc.

It's being worked on.

> ... in Tom Lehman's recent paper on the El Picacho ceratopian, his
>cladogram contains two paragenera: _Chasmosaurus_ (ancestral to but not
>including all the other ceratopine ceratopids) and _Torosaurus_ (ancestral to
>but not including _Triceratops_).

Word on the street is that some of the character choices in that paper have
a lot to be desired...

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

"There are some who call me...  Tim."