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Jaime Headden wrote:
I would try to resolve wether palaeanodonts are a natural grouping,
given some ideas that they may be a paraphyletic with regards to
that xenarthrans are paraphyletic with regards to palaeanodonts, any
relationship with pholidotes that are NOT based on parallel or convergent
The situation regarding 'palaeanodonts' is messy, to say the least. The
Palaeanodonta has a lot of baggage as a wastebasket taxon. The connection
between palaeonodonts, xenarthrans and pholidotes is similarly unresolved.
For example, _Eurotamandua_ was put in its own order by Szalay and Schrenk
(1998), called the Afredentata, and held to be unrelated to xenarthrans and
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.
Unfortunately this limited extant sampling may be enforcing the
less derived clades that would share common features with *Fruitafossor*,
the absence of *Orycteropus* and *Manis* are rather glaring as they had
mentioned in the text.
I agree that the aardvarks and pangolins are conspicuous by their absence
from the analysis. Nevertheless, the case for _Fruitafossor_ being a basal
mammal convergent upon xenarthrans appears pretty compelling to me.
To swing this thread back to dinosaurs (belatedly), I would point out that
dedicated myrmecophagy is not known for any Cretaceous mammal, AFAIK.
However, it has been suggested for the alvarezsaurids, which were widespread
in the Cretaceous period, having been found in Asia, Europe, North America,
South America, and Australia.