[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: [dinosaur] Latenivenatrix, new troodontid from Dinosaur Park Formation, Alberta (validity of Troodon)

One correction, though:

"That's why ... Titanosauridae are here to stay."

Actually, arguably not. Within Titanosauria there are several proposed and employed "families" (Saltasauridae, Nemegtosauridae, Aeolosauridae, potentially others). It is not at all certain which of these the Titanosaurus indicus material would belong to. If we agreed to put all of these in one family, that would be Titanosauridae. But if we regard them as distinct taxa, and cannot affirm where Titanosaurus goes, we can continue to not use "Titanosauridae".

On Fri, Aug 11, 2017 at 12:21 PM, David Marjanovic <david.marjanovic@gmx.at> wrote:
> I'd go one step further and abandon the name Troodontidae as well -
> and revert to using Saurornithoididae as the name for this clade. I
> know it's permissible to retain family-level taxa founded on nomina
> dubia (we still use Ceratopsidae, after all). But I still don't think
> it's a good idea (I also think the name Ceratopsidae should be
> abandoned).

It's not "permissible", it's required unless the family name is itself a nomen dubium, which is not automatically the case.

It's not like you get any choice in this matter as long as you stick to the ICZN. As long as the holotype tooth of *Troodon* fits the diagnosis of whatever "family" *Saurornithoides* belongs to and not that of any other "family", the name Troodontidae is valid and and Saurornithoididae is one of its junior synonyms. That's why Ceratopsidae and, yes, Titanosauridae are here to stay.

> As a nomen dubium, _Troodon_ would not be a genuine OTU
> (operational taxonomic unit),

OTU just means "line in a data matrix". Several specimen-level phylogenetic analyses (of other clades) have been performed.


Thomas R. Holtz, Jr.
Email: tholtz@umd.edu         Phone: 301-405-4084
Principal Lecturer, Vertebrate Paleontology

Office: Geology 4106, 8000 Regents Dr., College Park MD 20742

Dept. of Geology, University of Maryland

Phone: 301-405-6965
Fax: 301-314-9661              

Faculty Director, Science & Global Change Program, College Park Scholars

Office: Centreville 1216, 4243 Valley Dr., College Park MD 20742
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117

                        8000 Regents Drive
                        University of Maryland
                        College Park, MD 20742-4211 USA