Re: PhyloCode Discussion: Crowns, Panstems, and their Correspondence to each oth

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

> crown Mammalia only corresponds to the clade
> including monotremes, marsupials, and placentals, and only them and any
> descendant of that first ancestor of those three clades.

Yes.

> Meaning, "symmetrodonts" and zhangheotherids are _NOT_ crown mammals.

Most former "symmetrodonts", such as *Zhangheotherium*, _are_ crown mammals.
The cladogram here
http://www.palaeos.com/Vertebrates/Units/430Mammalia/430.100.html#Mammalia
and here
http://www.palaeos.com/Vertebrates/Units/430Mammalia/430.500.html#Spalacotheroidea
is based on pretty new primary literature, such as Luo et al. 2002. The
latter page even assigns *Zhangheotherium* to Spalacotheri_idae_.

(http://www.palaeos.com/Vertebrates/Units/430Mammalia/430.400.html expresses
discontent with Luo et al. 2002, though.)

Perhaps you were thinking of *Jeholodens*? This was described as being
outside the crown-group, but is now thought to be inside like all
"eutriconodonts".

> Also, since pan-stems are applied to _crowns_,
> Hesperornithes cannot become a pan-stem.

Did someone say they could?