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Re: *Fruitafossor*



On 5/4/05 7:29 am, "Tim Williams" <twilliams_alpha@hotmail.com> wrote:

>> This is a problem I was trying to point out with regards to the
>> presence of tubular teeth lacking enamel, since it HAS developed twice in
>> living mammals, given tubulidentates and xenarthrans.
> 
> It may be even more complicated than that.  The Madagascan taxon
> _Plesiorycteropus_ was separated by MacPhee (1994) into its own order
> (Bibymalagasia) separate from aardvarks.  I understand that this does not
> have universal support, with other authors putting _Plesiorycteropus_ back
> in the Tubulidentata.  If MacPhee is correct, then aardvarks may have their
> own example of convergence.
> 
    MacPhee's separation of _Plesiorycteropus_ was due to a lack of
phylogenetic support for connecting _Plesiorycteropus_ to _Orycteropus_, as
opposed to e.g. any other ungulate or myrmecophage. However, nor did he find
any direct evidence that _Plesiorycteropus_ was _not_ related to
_Orycteropus_. _Plesiorycteropus_ appears to be a horribly derived little
critter, with a lot of its skeleton giving intriguing but bewildering hints
- for instance, the structure of hips suggests an animal that spends a fair
amount of time at least sitting, if not moving, upright (comparable to
bears, baboons, etc.)
    Also, _Plesiorycteropus_ may have entirely lacked teeth. According to
MacPhee, we don't have any direct evidence, as the front half of the skull
hasn't been found yet; however, no promising isolated teeth have been found
anywhere.

    Cheers,

        Christopher Taylor