Re: BCF (was New Article in Experimental Zoology)

["David Marjanovic" <david.marjanovic@gmx.at>]

> > Maybe it's time to revise the concept of "mammal."
>
> They already did -- it's a crown clade.

Not only that, of course. The newest definition is another node:
{*Sinoconodon* + the crown}.

Luo Zhexi, Zofia Kielan-Jaworowska & Richard L. Cifelli: In quest for a
phylogeny of Mesozoic mammals, Acta Pal. Pol. 47 (1), 1 -- 78

p. 19:
"Mammalia as construed herein are a clade defined as the common ancestor to
*Sinoconodon*, monotremes, and crown therians, plus all the extinct fossil
mammals nested within these three taxa. This is equivalent [in content] to
the Mamaliaformes of Rowe (Rowe 1988: fig. 4, but not Rowe, 1993: fig.
10.2). We opt for this inclusive definition of mammals (e.g., Hopson 1994)
because it is consistent with widespread, traditional usage, and (as noted
above) because is [sic] has the virtue of being relatively stable with
respect to both living and fossil taxa. A crown-based definition of Mammalia
(Rowe 1986; McKenna and Bell 1997) clearly offers certain advantages
(Queiroz and Gauthier 1990, 1992; Rowe and Gauthier 1992), though there are
merits to other definitions as well ([...] [8 refs]). The current lack of
consensus on definition of Mammalia is an example of the perennial debate
surrounding vertebrate groups that have familiar, vernacular names, as well
as reasonably good fossil records documenting early phylogenetic
differentiation and anatomical transformations toward the crown groups
[...].
    Based on the foregoing definition, a primary character diagnosing
Mammalia is the presence of a craniomandibular joint comprised of dentary
condyle and squamosal glenoid. [...] [and others]"

A pretty wise decision IMHO.

> (Besides, it pretty doubtful that _Dimetrodon_ had mammaries....)

And here the next problem! The real definition for "bird" is "I know it when
I see it". Because both Aves and Ornithes _mean_ "birds", and we can't
switch off that, one or both should IMHO get a definition that as closely as
possible approaches that of "birds", or we'll have problems _forever_. I
think one of them should get a stem-based definition like {*Passer* >
*Velociraptor*, *Oviraptor*, *Segnosaurus*, *Saurornithoides*,
*Tyrannosaurus*, *Ornithomimus*}, which would not decide a priori if e. g.
*Archaeopteryx*, *Rahonavis*, *Jeholornis*, Alvarezsauridae, *Yandangornis*
and *Avimimus* are birds, but would not make traditional nonbirds birds
under any of the phylogenies I can think of. (Maybe add *Crocodylus* and
*Megalancosaurus* and *Homo* to the external anchors to satisfy
_everyone_...) But that's just me. :-)

Panaves is IMHO the best idea published so far for {*Passer domesticus* >
*Crocodylus niloticus*}, because it is the biggest clade that has ever been
called Aves. :-) I'd like Panornithes even better, because then the whole
word would be Greek, but well...

Crocodylotarsi/Ornithotarsi dichotomy? Under most phylogenies Crurotarsi is
more inclusive than Crocodylotarsi... still Ornithotarsi would be a good
idea. But maybe that should be put at or slightly before Dinosauriformes,
when the ascending process on the astragalus appears. <waffle, waffle>