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Re: Hanson 2006, Mortimer, Baeker response
Tim Williams writes:
>> I'm not sure I can agree with your position. For example, I've got
>> pretty bored of repeatedly writing "non-neosauropod sauropod"
>> recently; wouldn't it be nice just to define Eosauropoda as the
>> paraphyletic group (Sauropoda - Neosauropoda) and then just refer
>> to eosauropods?
> Although "non-neosauropod sauropod" is a cumbersome term, it is also
> explicit. I can't see any inherent reason why this term is bad.
> "Non-neosauropod sauropod" tells the reader *exactly* what you mean,
> without having to invent a new term.
"_Iguanodon_, _Megalosaurus_, their most recent common ancestor and
all its descendents" also tells the reader *exactly* what you mean,
but you wouldn't for that reason want to have to get by without the
name Dinosauria. Naming is always and only a convenience, since if
you're able to define the name then you're equally able to just trout
out that definition in place of the name. It doesn't follow that,
since it's "only" a convenience, it's not important.
> As for the paraphyletic group "Eosauropoda"... this would be
> difficult to define using species or specimens.
A man goes into the doctor's surgery. He lifts his arm and says,
"Doctor, it hurts when I do this." The doctor says, "Don't to that,
If you don't want to define Eosauropoda using species or specimens
(and _I_ certainly don't) then just use the clades that are its
motivation. Eosauropoda = (Sauropoda - Neosauropoda). What could be
> But if we are going to define groups by shared common ancestry (as
> phylogenetic taxonomy aims to do) then using paraphyletic groups is
Why? I've heard a lot of people parrot this position, but I've yet to
hear one person actually _argue_ for it. Merely stating it repeatedly
>> Note 11F.1. The following prefixes and suffixes imply
>> greater inclusiveness than the base name: Holo-, Pan-,
>> -formes, -morpha. The following prefixes imply lesser
>> inclusiveness than the base name: Eo-, Eu-, Neo-,
>> Proto-. The following prefixes imply mutual
>> exclusivity with the base name: Pseudo-, Para-. These
>> are not intended to be exhaustive lists.
> Now this is a great idea. One thing that bewildered me was having
> the clade Suchia inside the clade Pseudosuchia - though Pseudosuchia
> isn't used so much these days.
No? Senter (2005) reasserts its primacy, based on priority of
synonyms, as the correct name for the stem-based group (Crocs not
birds) under phylogenetic nomenclature. Senter, Phil. 2005.
Phylogenetic taxonomy and the names of the major archosaurian
(Reptilia) clades PaleoBios 25(3): 1-7.
> I also think it's a great idea to have a clade beginning with Eu- or
> Neo- to be inside the corresponding more-inclusive clade, especially
> given the situation regarding certain dinosaur clades.
I think it's _polite_, but whatever happened to taxonomic freedom?
/o ) \/ Mike Taylor <firstname.lastname@example.org> http://www.miketaylor.org.uk
)_v__/\ "It's great that we clicked so meanly into the groove as we
entered the run-in, just as we did last season. But the run-in
starts mid-August" -- Paul Tomkins.