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Re: origin of bats



Dave Peters (davidrpeters@earthlink.net) wrote:

<With regard to non-volant locomotory abilities: *Onychonycteris* hyper-folds 
its hands at the wrist/metacarpal joints, like all bats do. Evidently it was 
not using its hands like most quadrupedal tetrapods do.>

  Indeed. 1) It was flying with them, and 2) it was well-removed from virtually 
all potential outgroups in morphological space. This tells us we have yet to 
find even a close phylogenetic analogue to the ancestral group from which bats 
arose.

<And the bipedal hypothesis still stands.>

  Nothing in what you have shown in your email supports your previous position 
of a bipedal hypothesis. Could you care to elaborate on the paper's support or 
lack of refutation on the bipedal hypothesis, and what bipedal bats you have to 
argue your case? I can, as others have, cite several morphological features 
which make it difficult to evolve from bipedal locomotion[1]. Note that 
standing around on two legs does not result in any form of bipedal constraint 
on development, especially locomotorally.

[1] For example, the twisting of the entire hindlimb around its long axis, 
echolocation, cranial features adapted for three-dimensional auditory and 
visual senses which are absent in terrestrial quadrupeds OR bipeds, but are 
present in volant and arboreal animals, of which few are bipeds aside from 
birds (and they don't run around in trees).

  Cheers,

  Jaime A. Headden