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Re: Phylogeny of basal birds 2/3



----- Original Message -----
From: <Aegyptiacus@aol.com>

> how do you get *Ichthyornis* and *Hesperornis* more derived than *Anas*?

They share a reduced acromion, which *Anas* doesn't have.

Remember: this

+--*Anas*
`--+--*Hesperornis*
   `--*Ichthyornis*

and this

+--+--*Hesperornis*
|  `--*Ichthyornis*
`--*Anas*

is the same. (And if you switch *H.* and *I.* nothing changes either.) A
cladogram is a mobile: you can rotate it around every branch, and nothing
changes.