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Re: Fossil Discovery Threatens Theory of Birds' Evolution

>> Look at spirula and
graphitites, I know that neither is a vertebrate, but both evolved to look
exactly like another group.<<

I am not sure what this means. Spirula is a cephalopod that looks like a squid because it is one, or a close relative of one; coiled shells are cetrainly not unknown in cephalopods either, though Spirula is the only one with an internal coiled shell of which I am aware. I am not sure what "graphiphites" are but if you mean graptolites, they are apparently close relatives of the living acorn worms, which are somewhat distant relatives of chordates; a living acorn worm group, the pseudobranchs, has one species which produces quite graptolite-like colonies and was even considered to be a living graptolite by its discoverer. I am not sure what else you think these animals resemble. Certainly neither Spirula nor graptolites look like any vertebrate.

Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
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