[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]


In a message dated 95-11-23 08:20:25 EST, dwn194@soton.ac.uk (D.W.Naish)

>BCF seems at least appealing to many of those I have spoken to, but the
>consensus remains that it lacks the evidence, and, despite what George says,
>nothing convincing has appeared to make BADD (I think I prefer TH's term..
>was it again?) appear at all sterile. I wonder how many of those interested
>aware that similar, 'alternative' lineages have been hypothesised in the
>literature - for taxa other than archosaurs - , but - because they lack the
>material evidence - do not win significant support. I do not want to offend
>George by putting his ideas in the same boat as those who believe that
>are derived ichthyosaurs, or that mammals are direct descendants of
>but the principles seem much the same.

Those "Maniraptoran remains" are not necessarily those of dinosaurs as we
know them. They belong to very small animals indeed (e.g., teeth only a
millimeter or two tall), which BCF predicts directly whereas BADD adopts a
"wait-and-see" attitude. According to BADD, birds evolved from cursorial
dinosaurs similar to (though perhaps smaller than) _Deinonychus_ and
_Velociraptor_, which I think is completely wrong.

I don't understand your comment about whales and ichthyosaurs, etc., as being
like BCF. BCF is not an absurdity. I use the same cladograms that BADD
paleontologists generate--only I make a statement about the kinds of animals
that lie _on the branches of the cladograms_, which BADD either does not or
gets wrong.

There is other evidence besides hard fossilized skeletons, you know. If you
believe in the theory of evolution, and a little bit in parsimony, then you
know that there WAS a lineage that joins the first archosaur to
_Archaeopteryx_. Focus on that lineage for a bit. It started out as a small,
quadrupedal, lizardlike animal with an antorbital fenestra and turned into
_Archaeopteryx_. What anatomical changes did it undergo? Does it strike you
as reasonable that the animals on that lineage first became (for some unknown
reason) bipedal with small forelimbs and became large, ground-dwelling forms,
then _later_ reversed themselves, re-enlarged the forelimbs, and became

Or is it more reasonable that they _stayed_ small, scansorial forms with
large, grasping forelimbs, ever more capable of climbing, gliding, and later
flying, so that whenever a lineage branched off containing large, cursorial
forms, these would _automatically_ have to be bipedal with small forelimbs?