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Re: Archaeopteryx with bird book, was Re: Archaeopteryx flight



Tim Williams wrote:

I think there is good evidence that the naked head and neck is an adaptation to a particular type of scavenging, not just being a scavenger per se.<

Your qualification is a good one. Getting back to Archie however, let's assume (setting aside my own skepticism) that a relationship exists between bald-headedness among some large scavenging birds and that this condition is related to a specialized type of scavenging behavior. Under those assumptions, we are still left with the facts that: 1) Archie was small (relatively); 2) that views about its feeding behavior are almost entirely speculative; 3) that there is no evidence for a selection towards bald-headedness among extant small scavenging birds and that; 4) the anatomy of birds can be expected to result in a bias against the fossilized preservation of contour feathers. Given all that, the simplest interpretation of the absence of preserved head feathers on Archie is that it is exactly what would be expected in a fossil bird, given the preservational conditions. In my view, the Archie fossils do not support the view of some who seem willing to conclude that they demonstrate the *absence* of head feathers on Archie and, taking a second jump, that this condition is evidence of a scavenging lifestyle.


Pat