Re: Moasaurus

["Tim Williams" <twilliams_alpha@hotmail.com>]

ELurio@aol.com wrote:

> Okay, the Moa is extinct. I admit it. But it doesn't have any forlimbs
> either.

So what?  _Tyrannosaurus_ has tiny forelimbs, and those of _Carnotaurus_ are 
even smaller.  (And since _Carnotaurus_ is an Early Cretaceous abelisaur, 
perhaps its direct descendents of the Late Cretaceous lost them altogether.) 
 Hesperornithids also have tiny forelimbs.

> Plus it had feathers.

Grrrr....  So does _Caudipteryx_.  And, even if you don't want to call them 
feathers, a whole lot of Liaoning theropods have some form of feather-like 
integumentary structures which I'm willing to believe are ancestral homologs 
to bird feathers.

> Not to mention the fact that the recent
> molecular evidence shows that moas are closely releated to timinous, >who 
> can fly.

I don't doubt that moas are birds, just that these days, with all we know 
about theropods, you have to be very careful about identifying certain 
characters as uniquely avian.  Feathers, toothlessness, furcula, 
pygostyle...

> Well, Kangaroo Island was part of the Austrailian mainland as late as 
> twelve
> thousand years ago,

Makes no difference.  Emus lived on Kangaroo Island quite happily for 12,000 
years before the colonists wiped them out.  The emus didn't shrivel up and 
die as soon as Kangaroo island became isolated.  Large birds can live on 
tiny islands.  So, if most of NZ was submerged during the Caenozoic, I think 
the little islands that remained above water could have sustained 
populations of moas.  Perhaps the moas weren't as large as _Dinornis 
maximus_, but they were moas nonetheless.



> I'm not. Why? becuase there are NO moa fossils prior to the Pliocene. There
> are dinosaur fossils, marine fossils way up near the top of the mountains 
> on
> the southern big island. We're not talking about a gap or anything like
> celocanths or platypi.

Yes we are.  Absence of evidence is not always evidence of absence.  I'm not 
sure of the point you're making here.  The fossil record for the moas is 
non-existent before the Pliocene.  The Australian fossil record of the 
ornithorhynchids (platypus and relatives) is non-existent before the 
Miocene. (Though there is a tooth from the Paleocene of South America named 
_Monotrematum_ that has been considered a true ornithorhynchid; Cretaceous 
monotremes like _Steropodon_ most likely do not belong in the 
Ornithorhynchidae.)

The fossil record of spiny anteaters (Tachyglossidae) is similarly 
non-existent before the Miocene anywhere in the world.  _Megalibgwilia_ is 
the first we know of this lineage.  But, I'm willing to bet that both 
monotreme families evolved in Australasia, and that their ancestors were 
there as far back in the Cretaceous, it's just that we haven't found them 
yet.

(By the way, "platypodes" is the plural of platypus not platypi.  Sorry to 
be pedantic).

> Remember, theropods had arms with functional claws on them and big teeth.

Not all of them.  (See above.)

> Moas were pretty lazy beasts if the Maouris are to be belived.

Stupid moa.  Why didn't they get off their fat asses and evolve a defense 
against spears and nets.  They only have themselves to blame for going 
extinct!

(Actually, I thought the big dinornithids DID indeed put up a fight against 
the Polynesian hunters.  They didn't just sit around basking in the sun 
waiting for a Maori warrior to plunge a spear into its body.  Those long moa 
legs packed a lot of strength, and the clawed feet could be lethal.)


Tim


------------------------------------------------------------

Timothy J. Williams

USDA/ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163

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