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Re: African neognaths






From: <darren.naish@port.ac.uk>
To: zthemanvirus@hotmail.com
Subject: Re: African neognaths
Date: Wed, 24 Jul 2002 08:41:31 +0100

Hi

Re: your hypothesis about African endemism of certain
neognaths groups, you might be right.. have you seen
Cracraft's recent paper:

Cracraft, J. 2001. Avian evolution, Gondwana
biogeography and the Cretaceous-Tertiary mass extinction
event. _Proc. Royal Society London B_ 268, 459-469.

You say shoebills have never been found outside of Africa.
However there are a few (questionable) English Eocene
records of this group. You might be interested to know that
Rasmussen et al have postulated the giant Fayum
_Eremopezus_ as a possible shoebill relative. Here's what I
wrote about it on the DML a while back...

------------------
Rasmussen, D. T., Simons, E. L., Hertel, F. and Judd, A.
2001. Hindlimb of a giant terrestrial bird from the upper
Eocene, Fayum, Egypt. pp. 325-337.

Wow. _Eremopezus_ Andrews 1904 has been traditionally
regarded as an aepyornithid (even though little evidence
links any supposed African aepyornithid with _Aepyornis_
- this issue fully discussed in the paper) but the new
material described here shows that it's something else.
While larger than _Rhea_, it was not graviportal, nor as
cursorial as ostriches or rheas. The size and proportions of
the trochleae indicate fairly prehensile toes most like those
of _Balaeniceps_ and _Sagittarius_ so it's regarded as a
giant ?predator/omnivore, perhaps analogous with some
phorusrhacoids. Rasmussen et al. conclude that
_Eremopezus_ wasn't a ratite, but that it belonged to an
endemic African clade of uncertain affinities.
--------------------

Parrots: vasa parrokeets are very odd, but it's not sure that
they are the most basal living psittaciforms as you state.
Unpublished DNA evidence shows that Australasian parrots
are monophyletic and diverged very early on in parrot
history from the other groups. Regarding early parrots, you
ignore _Pulchrapollia_ from Eocene England (though
whether it's a parrot is now being questioned).

I agree with you regarding hornbills and hoopoes: evidence
indicates that they are probably African.


Thanks for your reply.I haven't read Cracraft's paper,but I'm really interested in what it says (I just can't get enough about avian evolution),could you please mail it to me?
I do wonder wether vasa parrots (they are parrots,not parakeets...tough both groups are terribly paraphyletic)were included in this particular DNA-study,they are so strikingly different from other parrots I doubt they have any close relationship with other living psittaciform species.Until proven otherwise I stay with my view that they are the most basal divergence of the psittaciform crown-group.The basal position of Australasian parrots is quite interesting....It might indicate parrots early on diverged in 4 lineages:
1.The most primitive parrots,the quercypsittids.(tough,with our little knowledge about them,they might represent several groups)
2.The vasa parrots,or,more accurately, the most primitive crown-group parrots.
3.The Australian group wich later on spread troughout the Pacific area and South-east Asia,even being able to spread via southern Asia,to Africa(Psittacula,Agapornis),Madagascar(Agapornis) and the Mascarenes(Psittacula,Mascarinus,Necropsittacus & Lophopsittacus,the latter three all recently extinct),and quite likely Europe as well.
4.An Afro-Neotropical assemblage containing all other parrots.
The early divergence of the latter two seems proof for an early Tertiary,southern hemisphere existence of crown-group parrots........like I wasn't convinced of that allready.




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