[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Asilisaurus kongwe

Oops, true, confused sister-grouping of Silesauridae and Dinosauria
with they being stem groups, which is not true at least for the
latter. Then, the Anisian silesaurid just indicate that in the Anisian
there were some beings more closely related to dinosaurs than any
other dinosauriform known now.

2010/3/4 Jay <sappororaptor@yahoo.com>:
> --- On Fri, 3/5/10, Augusto Haro <augustoharo@gmail.com> wrote:
>> From: Augusto Haro <augustoharo@gmail.com>
>> Subject: Re: Asilisaurus kongwe
>> To: keesey@gmail.com
>> Cc: dinosaur@usc.edu
>> Date: Friday, March 5, 2010, 3:17 AM
>> If the Silesauridae is the sister
>> group of the Dinosauria, then its
>> presence in the Anisian indicates an older age for the
>> Dinosauria (I
>> mean, as old as the Silesauridae). Also, for pterosaurs,
>> and the
>> stem-taxa leading to Scleromochlus, Lagerpeton and
>> Marasuchus but not
>> dinosaurs.
> Not necessarily, and i think the authors do discuss this very briefly.
> 'At the moment' silesaurids are the sister taxon to Dinosauria, the 'at the 
> moment' part is important because if various other new archosaurian taxa were 
> discovered, and found closer to dinosaurs than to silesaurids, these new taxa 
> would become progressively closer sister taxa to dinosaurs (than silesaurids 
> are). What this means in terms of age is that the oldest dinosaurs need not 
> have been as old as the oldest silesaurids (re-note that dinosauria is 
> node-based [Ornithischia + Saurischia], thus allowing for the above mentioned 
> hypothetical sister taxa to be identified, and hence better constraining the 
> earliest age for dinosaurs in future).