... Science Frontiers ONLINE No. 66: Nov-Dec 1989 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Bird That Smells Like Cow Manure Pity the poor hoatzin. This "extremely primitive" bird is usually described as being just a step beyond the reptiles. The hoatzin clambers around the jungle foliage using functional claws on its wings. This certainly sounds "primitive." Then, we have that awful smell! A hoatzin feeds its chick a regurgitated mush of partially digested leaves. But perhaps we have been wrong about the hoatzin. It's all just bad press. A. Grajal et al have just discovered that this South American bird utilizes foregut fermentation in digesting its diet of leaves. In fact, the hoatzin is the only bird that has evolved this useful capability. Cows, sloths, and a few other mammals and marsupials evolved foregut fermentation. It is hardly a primitive development! Aside from the smell of fermenting vegetable matter, the hoatzin is a rather remarkable animal - more advanced and well-adapted to its environment than previously thought. Grajal et al remark on all the advantages that foregut fermentation confer on the hoatzin and how remarkable it is that this digestive process can be accomplished in such a small volume (cows have huge stomachs). How did the hoatzin hit upon this mechanism before the mammals did? Why didn't other birds "adopt" it? Grajal et al speculate about this hoatzin advance: "Their highly specialized digestive strategy may have arisen from an ancestral nonobligate folivore because of an evolutionary ...
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... emotionally) over how Archaeopteryx fossils should be interpreted. The scientific acrimony centers on whether this ancient bird really evolved from small theropod dinosaurs. Prevailing theory has it that these dinosaurs first evolved feathers to keep warm and then used their feathered "arms" to help capture insects, and so on, with some aimless flapping, to the attainment of true flight. A rival, officially frownedupon theory has it that birds evolved from tree-dwelling reptiles that evolved feathers to break their falls while jumping from branch to branch! [Somehow, neither theory strikes a realistic chord. Why couldn't feathers have evolved solely for the purpose of flight? Answer: because evolutionists cannot countenance purpose in nature. WRC] One reconstruction of Archaeopteryx. There is a remarkable superficial resemblance to the living South American hoatzin. Young hoatzin even sport claws on their wings. Anyway, the latest fusillade in the Archaeopteryx wars was fired by A. Feduccia in Science. Feduccia demonstrated that the claws of Archaeopteryx are sharp and curved like those of modern arboreal birds and quite unlike either terrestrial birds or theropod dinosaurs. In concluding his long, detailed paper, Feduccia highlights nine additional features of Archaeopteryx that make it look like a modern arboreal bird; i.e ., barbed feathers, asymmetrical flight feathers, etc. V. Morell quotes Feducci as saying, "Paleontologists have tried to turn Archaeopteryx into an earthbound feathered dinosaur. But it's not. It is a bird, a perching bird. And no amount of 'paleobabble' is going to change that." (Feduccia, Alan; ...
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