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Re: The Evolutionary Mosaic (wasTrees Down or Ground Up?)



Luis Rey wrote:

Isn't the mosaic puzzle in turn a clear picture of evolution at work? Following ground up reaching the tree heights or high canopy gliding from tree to tree strategies we are seeing a 'free-for all' set of strategies in animals that were
not absolutely specialized to what we call now sophisticated flight 'yet'. At least some of them.
Just as sifakas... arboreal but not flyers. Whatever adaptation that helps you to survive stays. And also as sifakas: I think there would be NO fully formed feathers if (I'd say all) more primitive dinosaurs were not already covered with
a precursor of feathers that served as insulatory integument. Hats off to Prum.


None of these animals were compelled to become modern birds. But some of these animals were already getting fine tuned for extreme sophisticated flight adaptations and an absolute dependency on those... and these were to become the
birds we know today, the rest went extinct.


Just what I think. I guess Mesozoic avian evolution was very messy with mass convergism,reversals and things unlike anything found in modern birds.The common ancestor must have been a very primitive creature wich descendants evolved in numerous ways,mostly getting more and more specialised for flight,but nearly as often evolving into something else. (dromaeosaurs,oviraptorosaurs,therezinosauroids,alvarezsaurs,patagopterygids,hesperornithids and whatever else might belong here..)

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