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Re: [dinosaur] Diplodocus status



As I said in my ICZN comment-

- There isn't even agreement that Diplodocus longus IS undiagnostic.
- Even IF Diplodocus longus was undiagnostic, undiagnostic species CAN be the 
type species of diagnostic genera.  There's nothing in the ICZN arguing against 
that.  That's a myth started by Wilson and Upchurch (2003).
- The argument about future-proofing for nomenclatural stability has zero 
urgency because all parties involved agree Diplodocus longus is definitely the 
same genus as D. carnegii, even the authors who petitioned the ICZN in the 
first place.  Tim et al. would be arguing for an official nomenclatural change 
based on a case that nobody thinks is true or even likely.
- If we continue with this philosophy of designating the most complete species 
as the type species or the most complete specimen the neotype, there go the 
holotypes of Masiaksaurus, Majungasaurus, Marshosaurus, Acrocanthosaurus, 
Megaraptor, Albertosaurus, Tarbosaurus, Tyrannosaurus, Deinocheirus, 
Struthiomimus, Dromiceiomimus brevitertius and D. samueli, Suzhousaurus, 
Therizinosaurus, Incisivosaurus, Caudipteryx, Chirostenotes, Elmisaurus, 
Citipes, Avimimus, Conchoraptor, Anchiornis, Archaeopteryx, Microraptor, 
Saurornitholestes, Velociraptor, Deinonychus, Utahraptor, Sapeornis, 
Confuciusornis, Gobipteryx, Archaeorhynchus, Patagopteryx, Gansus, Ichthyornis, 
Baptornis and Hesperornis; and the type species of Alioramus, Tarbosaurus, 
Ornithomimus (as far as the lit is concerned), Archaeopteryx, Microraptor, 
Sapeornis, Confuciusornis and Gobipteryx (among Mesozoic theropods).  It's a 
bad philosophy.

Mickey Mortimer


From: dinosaur-l-request@mymaillists.usc.edu 
<dinosaur-l-request@mymaillists.usc.edu> on behalf of Tim Williams 
<tijawi@gmail.com>
Sent: Thursday, October 15, 2020 4:27 PM
To: dinosaur-l@usc.edu <dinosaur-l@usc.edu>
Subject: Re: [dinosaur] Diplodocus status 
 
I also thought _D. carnegii_ should replace _D. longus_ as the type species.  
So I disagreed with the ICZN decision.

Yes, I understand that, technically, a case could be made (and in fact was 
successfully made) that the _D. longus_ holotype is diagnostic - barely.  But 
this is beside the point.  For the sake of nomenclatural stability, and to 
'future-proof' _Diplodocus_ as a valid genus, I thought the genus was 
infinitely better served in having _D. carnegii_ as the type species, rather 
than _D. longus_.  




On Fri, Oct 16, 2020 at 6:28 AM Mike Taylor <sauropoda@gmail.com> wrote:
Yes, it's based on Diplodocus longus: the ICZN rejected a petition to change 
the type species to D. carnegii a couple of years ago. I submitted a comment in 
support; IIRC Mickey Mortimer submitted one against :-)

What does this mean? The petition was rejected partly on the grounds that the 
D. longus material was (wrongly in my opinion) considered sufficiently 
diagnostic, so the genus is OK. (I mean, by definition it's OK nomenclaturally, 
but it should be OK taxonomically.) But in practical terms, everyone who works 
on sauropods still means "kinda like D. carnegii" when they say "Diplodocus". 
No-one cares about the type material. So all that's happened is that the 
rejection of petition means that the nominal type species is not the same as 
the effective type species. If it ever turns out the D. carnegii is generically 
separated from D. longus, you can bet for sure that it will be carnegii that 
retains the name Diplodocus, whatever the ICZN may say.

-- Mike.




On Thu, 15 Oct 2020 at 20:14, Ethan Schoales <ethan.schoales@gmail.com> wrote:
What's the status of Diplodocus's type genus? Is it still D. longus, which is 
apparently dubious? 

I hope Diplodocus doesn't end up as a dubious genus.