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Re: Gansus Bird-Dino Connection - Penn Press Release

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?