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> Date: Thu, 14 Apr 2016 10:25:25 +1000 > From: tijawi@gmail.com > To: dinosaur-l@usc.edu > Subject: Re: [dinosaur] Tyrannosaurs and Deinodons (was re New Konzhukovia species (temnospondyl) from Permian of South America + Early Triassic polar coprolites + more papers > > Anthony <keenir@hotmail.com> wrote: > > > Then what's the problem? the -oidea and such would be a legacy of its past, > > and would be less noteworthy than that we English-speakers say we wear shoes > > and not shoen (its the same thing - just in two early modern dialects) > > I thought the problem was clear - it was spelled out in Matt's post. > The ICZN and phylogenetic nomenclature (PN) have different rules > regarding how to treat certain taxa (coordinated family-level taxa - > such as families and superfamilies). > > In the eyes of the ICZN, the -oidea of Tyrannosauroidea designates it > as a 'superfamily'. As such, it is linked to Tyrannosauridae, which > the ICZN regards as a 'family'. Both Tyranosauridae and > Tyrannosauroidea therefore fall under the jurisdiction of the ICZN, > and must conform to rules regarding priority. A strict application of > ICZN rules would say that Tyrannosauridae should be replaced by > Deinodontidae - because both _Tyrannosaurus_ and _Deinodon_ belong in > the same family, and Deinodontidae was named first. As an extension > of this, Deinodontoidea would replace Tyrannosauroidea, under ICZN > rules. I think this approach is a bad idea. Were Deinodontidae and Deinodontoidea actually created, or is their existence assumed based on backforming from _Deinodon_ & the higher clades which were named for _Tyrannosaurus_? (I've seen backforming in linguistics, but not in nomenclature) > Under PN, on the other hand, Tyranosauridae and Tyrannosauroidea are > defined as clades. Being a 'family' and 'superfamily' makes no > difference at all - they are treated the same as any other clade. > Deinodontidae and Deinodontoidea are not defined as clades, so they > have no standing under PN. They do not exist. This is fine by me. So, because Cope and Marsh forgot to define Deinodon's clades, we can't use it? :) Why not define it as "Tyrannosaur(__) + {insert name here}" ? for example, if the Tyrannosaurids are defined by, among other things, having two-fingered hands, let Deinodontidae/oidea be the Tyrannosaurids+the three-fingered species that gave rise to them. (or was a sister species to the mother of the Tyrannosaurids) > > if Coeluroidea gets defined next week or next year, it has priority over the > > older definition of Tyrannosauridea? even if that's true (and not an > > understandable misinterpretation or misreading), wouldn't that only matter > > if Coeluroidea is given the exact same definition of Tyrannosauridea? > > It doesn't matter to ICZN. According to ICZN, a family (or > superfamily) doesn't need a definition in order to be valid. > > This is how ICZN rules regarding families (-idae) and superfamilies > (-oidea) complicate things in PN. PN says a clade needs a definition > in order to be valid. So...to make sure I'm understanding this...under PN, it doesn't matter if _Ceratops_ is a valid genus -- it can be used as a higher clade name anyway? > The ICZN only looks at which family was *named* > first. It doesn't care about phylogenetic definitions. So, the ICZN assumes that, if something has a name, there's no need to worry about finding a place for it - it already has one? That does sound handy. > (In its defense, the ICZN Code was crafted in the epoch of Linnaean > ranks, long before PN came on to the scene. But now it's time to move > on, and abandon the ICZN's role in the naming of families etc. The > ICZN can stick to genera and species.) But why stop at that half-measure? Why not give the boot to the ICZN genera and species (and subspecies and superspecies and subgenera and other things I've heard of over the years) ? What makes genus and species worth saving, when nothing else is? |