Message 2002-04-0012: Re: eumaniraptoran systematics

Mon, 29 Apr 2002 15:52:26 -0700 (PDT)

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Date: Mon, 29 Apr 2002 15:52:26 -0700 (PDT)
From: "T. Michael Keesey" <>
To: "Jaime A. Headden" <>,, Mailing List - PhyloCode <>
Subject: Re: eumaniraptoran systematics

(Forwarded to the PhyloCode Mailing List, as there are several relevant

(Note to the Dinosaur Mailing List: In a previous post I appear to have used
_Troodon mongoliensis_ repeatedly where I should have used the type species _T.

--- "Jaime A. Headden" <> wrote:
>   The the more inclusive _Paraves_ Gauthier, 1988, Paraves(_Deinonychus
> antirrhopus_ <-- _Oviraptor philoceratops_) [I think this is the intended
> structure, without using "clade" at the beginning of the formula, as it
> appears to be an "insert clade name here" null entry]...
I don't think so, or they would have italicized it. Plus, it's redundant to
have to list the name twice. And using just "Clade" gives us a system for
referring to unnamed clades, e.g. Clade(_Oviraptor philoceratops_ + _Vultur
gryphus_) (mentioned below).

The "Clade(x)" notation is also consistent with mathematical and computational
function notation. Perhaps when species are added to PhyloCode, a similar 
"Species(x)" notation could be added, e.g. _rex_ Osborn 1905 = Species(CM 9380)
(meaning that the species' holotype is CM 9380 -- species based on cotypes
could use comma-separated lists, etc.).

>   I still like the Wagner-Buchholz notation, sorry guys, because it's not
> so ridiculously over-structured: Paraves = {Deinonychus <- Oviraptor}. The
> arrow instead of the "greater-than" sign is used because this does seem to
> be an advantage of the PhyloCode's notation ...

I agree about the "greater-than" sign (sorry guys!!).
But if you just get rid of the "Clade" part, they're pretty similar.

> and note, you can still
> change the notation before pre-emminent publication!

Draft PhyloCode only says you "may" abbreviate them thusly, anyway. Other forms
of abbreviation aren't necessarily ruled out, I think.

>   And this leaves the *Oviraptor* + *Vultur* (for which I still say
> *Passer* is probably the better choice as it is much more personally
> available and observable than an old-form carno-stork like *Vultur*) clade
> unnamed, even though Sereno redefined Hutchinson and Holtz' explicit
> definition to represent the maniraptoran node. There is a definition of
> that sort with this, so Sereno supplied, in effect, a nameless clade,
> which needs a name. I have one available, of course ....

I think it should be named.
>   In the event that *Troodon* is dismissed as an _nomen dubium_, so to
> does it take any eponymous taxon names with it, including Troodontidae,
> and if Gilmore actually published Troodontoidea, that to.

?? I don't see any rules saying that in any code. (Or did we discuss this
already and I forgot?)

Seeing as the designation "nomen dubium" is subjective, this would be a tough
rule to enforce.

> The available
> name for the group is Saurornithoididae Barsbold, 1974. Adding -oidea is
> not neccessary, nor is inclusion of Saurornithoid- anything.... An
> entirely new word may be formed for this purpose, or use of another
> internal specifier for eponymous purposes. One may have, then,
> Byronosauria, etc.... Troodonts have only two truly universal
> autapomorphies that are not equivocal, and that is the increase and
> morphology of their teeth, and the elongate and enlarged maxillary
> fenestra. Thus, the snout is autapomorphic, and a name like "Psalidorhina"
> could be instructive to this purpose ("scissor snouts").

But I think it would be more elegant and easier to remember if the sister
groups mirrored each other: two stem-based sisters ending in "-oidea" with
node-based "-idae"-ending taxa inside.

It also occurs to me that Clade(_Dromaeosaurus albertensis_ + _Troodon
formosus_) could be coined "Dromaeosauriformes". Taxa ending in "-iformes"
traditionally include those ending in "-oidea" (in vertebrates, anyway). (It
also sort of emphasizes their proximity to _Aves_, since all "ordinal" avian
taxa end in "-iformes".)

Paraves = (Vultur <- Oviraptor)
`--Eumaniraptora = (Vultur + Deinonychus)
   |--Avialae = (Vultur <- Deinonychus)
   `--Deinonychosauria = (Deinonychus <- Vultur)
      `--"Dromaeosauriformes" = (Dromaeosaurus + Troodon)
         |--Troodontoidea = (Troodon <- Dromaeosaurus)
         |  `--Troodontidae = (Troodon + Sinornithoides)
         `--Dromaeosauroidea = (Dromaeosaurus <- Troodon)
            `--Dromaeosauridae = (Dromaeosaurus + Velociraptor)
               |--Dromaeosaurinae = (Dromaeosaurus <- Velociraptor)
               `--Velociraptorinae = (Velociraptor <- Dromaeosaurus)
(It also occurs to me that naming the stems "Troodontia" and "Dromaeosauria"
instead of Troodontoidea and Dromaeosauroidea would work, too, especially given
the widespread use of the vernacular forms "troodont" and "dromaeosaur" for
these groups.)

The problem with names based on traits, like "Psalidorhina", is that either
1) They are given node- or stem-based definitions, which rarely if ever
correspond precisely to presence of the trait (e.g., _Amniota_, discussed
recently on the Dinosaur Mailing List), or
2) They are given apomorphy-based definitions, which frequently prove difficult
to apply with precision.

(Although it is kind of a cool name.)

=====> T. Michael Keesey <>
=====> The Dinosauricon <>
=====> BloodySteak <>
=====> Instant Messenger <Ric Blayze>

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