Re: Gansus Bird-Dino Connection - Penn Press Release

[Tim Williams <twilliams_alpha@hotmail.com>]

Michael Habib wrote:

> Frigates can nest in trees, actually, despite not being able to 'perch' in 
> the technical sense of the word.

By perching in the 'technical sense' do you mean one or more toes is capable 
of opposing two or more other toes in a prehensile grip?

> Galliform birds also run (via WAIR) or fly into trees, and they do not have 
> a perching foot, either.

Nevertheless, the hallux of two modern galliform groups (cracids and 
megapodids) inserts on the metatarsus at the same level of the other toes.  
To use the ornithological term, the hallux is 'incumbent' not 'elevated'.  
Megapodes live on the ground and use the long hallux for mound-building, but 
the cracids (guans, curassows, chachalacas) roost in trees and use the 
hallux to oppose the other toes.  Cracids would be true perchers, wouldn't 
they?

Cheers

Tim