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Re: Fossil Discovery Threatens Theory of Birds' Evolution
In a message dated 6/24/00 1:09:43 PM, firstname.lastname@example.org writes:
<< That is a problem. I say that a flightless bird _is_ a dinosaur, but other
people don't. What we need is a diagnostic feature that we can find and say
"yes! That's a dinosaur". We can look at mammals' jawbones (or teeth) and
seperate them from mammal-like reptiles, and that has made things much
The defintion of "mammal" has changed in the last decade or so. How do you
know that a live Olyagopolis would look like a reptile? As to the former
comment, I'm pretty sure that's right. Postosucius, has a theropod-like
skull, but not a theropod-like body.
The problem is that you've got this thing sitting there. I remember my
geometry teacher saying something to the effect that to prove something true,
you need many logical and mathamatical steps, but to disprove it, all you
need is a single equasion.
You've got all these elegant, logical and mathematical steps, and I've got
<<Convergence is quite powerful, but it can only work with what it has.
look a great deal like fish, but their tails move up/down not side/side
the up/down movement is how mammals' spines move when they run. If birds had
evolved from dinosaurs, but from some crocodile-like ancestor, they would
have displayed all of those dinosaur-like traits by mere convergence. If
Longuisquama was quadripedal (which seems to be the consensus, although, to be
fair, the hindlimbs aren't there so we don't know), then it would have given
to a race of quadripedal birds. Sound crazy, well quadripedal mammals gave
to quadripedal bats, didn't they?
Hey, life has gotten some pretty weird children. Look at spirula and
graphitites, I know that neither is a vertibrate, but both evolved to look
exactly like another group.