RE: Camarasaurs (was Re: Dinosaur Genera List corrections #118)

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> NJPharris@aol.com
>
> > The general "camarasaur" like skull seems to be the basic sauropod
> >  condition, found in basalmost forms (_Shunosaurus_),
> >  euhelopodid/mamenchisaurids (_Omeisaurus_, _Euhelopus_: like
> Dinogeorge, I
> >  wouldn't be surprised if Euhelopodidae really does contain
> _Omeisaurus_,
> >  _Euhelopus_, and _Mamenchisaurus_), _Jobaria_, and basal macronarians
> (i.e.,
> >  _Camarasaurus_).
>
> Argh.  So is there still an actual Camarasauridae, or has
> Macronaria simply
> turned into a bunch of serial outgroups to _Saltasaurus_?? :-S

Insofar as there being a "Camarasauridae" comprised of _Camarasaurus_ and
something else, supported by synapomorphies in a phylogenetic analysis: no,
no one has ever recovered such a taxon in any published study.

"Camarasauridae" sensu McIntosh (in The Dinosauria) is almost certainly
paraphyletic: _Euhelopus_ is EITHER part of a greater Euhelopodidae with
_Omeisaurus_ and _Mamenchisaurus_ OR the sister taxon to the titanosaurs and
_Opithocoelicaudia_ is a titanosaur; _Aragosaurus_, _Tienshanosaurus_, and
_Chondrosteosaurus_ have not been subjected to phylogenetic analysis, so
theoretically one or more of these might yet turn out to be closer to
_Camarasaurus_ than to any other dinosaur.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
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