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


With reference to my comments on the suggestion that the Green tree monitor
(_Varanus prasinus_) could be a protobird analogue, Wagler says:

>         And this makes it a good protobird?!?!?!  A prehensile tail?  Just
> where is there any evidence for THAT in bird evolution. 

You've missed the point, I do concede that it is all my fault however. First
of all, I never said anything about prehensile tails figuring in bird
evolution: I mentioned them as they may come in somewhere along the line
amongst small arboreal archosaurs/archosaur-relatives (e.g. megalancosaurs)
[sigh - - in which case it *is* involved with bird evolution]. Secondly,
what with my mention of _V. prasinus_, I said 'it has been suggested to me'
that it is a protobird analogue. Feduccia and his advocates require just
such an animal for their views.

What strikes me as remarkable is that there is a varanid with a prehensile
tail - part of the fantastic diversity that is _Varanus_ (I shall not
explore the implications for dinosaur taxonomy).

> I bet it has a long trunk too.

It does.

> No potential bird progentior could have loooked like a narrow-tailed
> flexible-limbed, weird thing like a monkey.

The dino-l community is currently exploring a broader topic than the origin of
bird flight, in which case monkeys and lemurs are appropriate. What worries me
is that I keep on commenting on mammals. I can only emphasise that I think this
necessary as observations on _their_ evolution lead us to consider the broader
issues in which archosaurs figure.

Some things I intend to follow up are:

1) Details on the gliding viverrid.
2) _Leptictidium_: someone (Nick Longrich?) wrote about this recently. The case
for it being a bipedal runner, like a small theropod, rather than a Springhare
(_Pedetes_)-style hopper, has fallen apart with a new analysis by Frey et al.
It probably did hop after all.
3) Miacoid evolution. Is degeneration of manual digit 1 in some carnivorans
really the result of descent from the trees? Incidentally, a theory putting all
of early mammal origins in the trees _was_ put about in recent decades. 

"Why, I've seen more realistic dinosaurs come out of a cereal packet!"