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RE: Rugops: some questions
> -----Original Message-----
> From: Nick Pharris [mailto:email@example.com]
> Sent: Tuesday, June 08, 2004 9:37 PM
> To: firstname.lastname@example.org
> Cc: email@example.com; firstname.lastname@example.org
> Subject: RE: Rugops: some questions
> Quoting "Thomas R. Holtz, Jr." <email@example.com>:
> > That might well be, but they evidence they use to support this
> is the lack
> > of a hierarchical structure within Abelisauroidea that matches any
> > particular break up pattern.
> Actually, the phylogeny presented in the
> _Rugops_/_Spinostropheus_ paper is
> consistent with the Africa-first hypothesis:
> +--UNNAMED NODE
> +--CARNOTAURINAE (Rajasaurus + (Majungatholus + Carnotaurus))
> Note that ABELISAURIDAE are Pan-Gondwanan, but the interior node
> (Abelisaurus +
> CARNOTAURINAE) is restricted to S.Am. and Indo-Madagascar. But as Dr. Tom
> noted, we're still a long way from finding everything there is to
> be found.
In point of fact, it is equally consistent with the Africa-first vs. E/W
split hypotheses, because (and here is the important parts):
1) we don't have contemporary abelisaurids from the non-African Cenomanian
(except possibly Ilokelesia)
2) we don't have Campano-Maastrichtian abelisaurids from mainland Africa.
IF the latter were discovered, and these consistently fell outside the
Abelisaurus + Carnotaurinae clade, THEN we'd have support for Africa-first.
But since we don't have those yet, the phylogeny discovered is equally
consistent with both break-up scenarios.
Thomas R. Holtz, Jr.
Department of Geology Director, Earth, Life & Time Program
University of Maryland College Park Scholars
College Park, MD 20742
Phone: 301-405-4084 Email: firstname.lastname@example.org
Fax (Geol): 301-314-9661 Fax (CPS-ELT): 301-405-0796