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

[Matt Martyniuk <martyniuk@gmail.com>]

Keep in mind, if that were the standard, Titanosauridae would be a nomen dubium 
but e.g. Deinodontidae wouldn't (unless you elevated Tyrannosaurinae and 
Albertosaurinae to "family" rank). The situation with Deinodontidae is a nearly 
exact parallel to Troodontidae. It would be hard to think of a single standard 
that would uphold one while rejecting the other, except using priority of 
definition/only recognizing taxa defined as clades.

Matt Martyniuk

On Aug 11, 2017, at 1:15 PM, David Marjanovic <david.marjanovic@gmx.at> wrote:

>> 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".
> 
> Oops, that's true; if Titanosauridae is indistinguishable from two (or more) 
> families that can be distinguished from each other, it is a nomen dubium. I 
> hadn't been paying enough attention to titanosaur nomenclature over the last 
> few years.