Brooding feathers, Chinese dinobirds

[Jeff Hecht <jhecht@world.std.com>]

While we all give John Ostrom and Greg Paul much-deserved congratulations
for their visions of feathered dinosaurs, the National Geographic
reconstructions of longish arm feathers insufficient for flight brings to
mind Tom Hopp's suggestion at Dinofeat (and earlier today on the list) that
wing feathers could have evolved for brooding.

Paleontologists I ask about the idea point out -- justifiably, so far --
that it's a hard hypothesis to test. Behavior doesn't fossilize well. But
the theory is in play now, and Caudipteryx and Protarchaeopteryx seem
consistent with brooding. They may be consistent with other behaviors as
well, but I'd like to hear the idea get a proper hearing.

Another thing that much intrigues me is how many species/genera the Chinese
deposits sample? We seem to have a nice sampling of critters ranging from
scaly dinosaurs through the 'downy' Sinosauropteryx, the flightless but
feathered Protarchaeopteryx and Caudipteryx, to the feathered and very
abundant flighted bird Confuciusornis. What else are we missing? Could all
those Confuciusornis be the equivalent of the assorted sparrows, swallows,
woodpeckers and robins flying around a modern lake -- but not yet
differentiated because no one has studied enough of them as carefully as
Ji, Currie, and Norell did Protarchaeopteryx and Caudipteryx (which they
originally thought was just another Protarchaeopteryx).

-- Jeff Hecht