Re: Asilisaurus kongwe, the Oldest Avian-line Archosaur and the Early Diversification of Ornithodira

[Daniel Madzia <daniel.madzia@gmail.com>]

> T. Michael Keesey wrote:
> I agree that the term "avian-line" is confusing -- I'd usually
> interpret it as "ancestral to Aves", i.e., the avian lineage, but in
> this context they are clearly using it to refer to the avian total
> clade (otherwise known as "Avemetatarsalia", "Panaves", or
> "Pan-Aves"). "Avian-branch" might be a little clearer.

My native language is Czech (ehm... actually a mixture of modern
Czech, very old Polish and deformed German) so I may not feel this
wording in the same way as you, but I don't think the term
"avian-line" is not as clear as "avian-branch" (in the "total-clade"
sense). The only problem I see here is that although they wrote that
"[b]y the Middle Triassic, Archosauria had diverged into two lineages:
the crocodilian line (Pseudosuchia) and the avian line (Ornithodira,
including dinosaurs)", Ornithodira is a node-based clade (contains
only pterosaurs and dinosaurs; not everything more closely related to
birds than to crocodiles), so the proper form should not refer to the
total clade (*Pan-Aves*, if you wish; I do); ergo both "avian-line" as
well as "avian-branch" would be confusing here.

Anyway, Silesauridae has two phylogenetic definitions now. Langer et
al. (2009) provided the first one: "(*Silesaurus opolensis* â
*Heterodontosaurus tucki* or *Marasuchus lilloensis*)", and Nesbitt et
al. (2010) the second one: "(*Silesaurus opolensis* â *Passer
domesticus*, *Triceratops horridus* or *Alligator
mississippiensis*)...

Literature:
Langer, M. C., Ezcurra, M. D., Bittencourt, J. S. & Novas, F. E. 2009.
The origin and early evolution of dinosaurs. Biological Reviews 84:
1â56.

Nesbitt, S. J., Sidor, C. A., Irmis, R. B., Angielczyk, K. D., Smith,
R. M. H. & Tsuji, L. A. 2010. Ecologically distinct dinosaurian sister
group shows early diversification of Ornithodira. Nature.
doi:10.1038/nature08718.

Best,
Daniel
--
Daniel Madzia
web: www.wildprehistory.org
mail: daniel.madzia@gmail.com
skype: danielmadzia