Re: chicken wing-claws

["Tim Williams" <twilliams_alpha@hotmail.com>]

David Marjanovic wrote:

> > The analysis by Mayr and Clarke (2003), using 148 osteological and soft
> > tissue characters, found _Opisthocomus_  (hoatzin) to be the sister 
> taxon
> to
> > Cariamidae (seriemas).
>
> OH NOOOOOOO... Not one MORE totally utterly new and unprecedented
> hypothesis!!!

I was surprised to learn that the hoatzin-seriema clade is not new.  Olson 
(1985) proposed a close relationship between the two groups, as part of a 
more inclusive Sth American neognath radiation.  (Mayr and Clark [2003] 
regard a Musophagidae+Cuculidae [turacos+cuckoos, respectively] as sister 
taxon to the _Opisthocomus_-Cariamidae clade - and they don't support 
putting certain falconiform taxa in this clade, as Olson does.  They also 
regard this O-C clade as highly derived within the Neognathae - a long way 
from the Galloanseres.  Livezey and Zusi [2001] placed seriemas at the base 
of the Neognathae.).

Anyway, if seriemas and hoatzins are closely related, then this clade would 
have to include phorusrhacids.  At least one phorusrhacid (_Titanis_) has a 
mobile manual digit (the first, I think), and juvenile hoatzins have free 
manual digits (so they can climb) - is this a potential synapomorphy for
this clade?



Tim

_________________________________________________________________
Tax headache? MSN Money provides relief with tax tips, tools, IRS forms and 
more! http://moneycentral.msn.com/tax/workshop/welcome.asp