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Re: Today Cordillera, tomorrow the world.



Ceratopsids were always unknown in the east<
As mentioned onlist earlier today, absence of evidence is not always evidence of absence. With hadrosaurs in the Eastern US, and the Western US (all the way to California!), I don't see what would prevent ceratopsids migrating across the

How far might they have gotten in the latest Maastrichtian, when seaways were vanishing?<
Um...New Mexico?

"Betasuchus"<
How much of this animal is known?

the tentative identification of Thescelosaurus from Romania.<
How tenative?

In addition to a probable America-Europe link<
I thought that this was more than probable...more like, "Widely accepted." Am I this far behind on paleogeography?

Tarascosaurus, in particular, supports a Europe-Africa connection, inasmuch as abelisaurs are otherwise known only from Gondwana.<
Would the presence of _Baryonx_ in England, with the ocurance of other spinosaurs in Africa strengthen this (despite it being earlier)?

Krause et al determined that virtually all extant Malagasy vertebrates arrived post-Cretaceous, undermining the notion of an isolated Madagascar by the latest Cretaceous.<
How does this eliminate an Ice Age land bridge?

Czerkas once mentioned probable South American tyrannosaurs, based on
"fragmentary fossils."  This seems unverified<
And therefore not very strong evidence.

but together with Notoceratops is intriguing<
If there, why not the Eastern US?

Cousin et al wrote "...theropods were briefly the dominant group<
Really? So there were predatory stegosaurs beforehand, and after? What other predators would be dominant in SA then?

That is intriguing as it suggests an alternative to climatic change as the cause of the extinction of Ampelosaurus, Rhabdodon, and Struthiosaurus.<
What's the alternative? _T. rex_?

Composed mostly of weak defenders, the w. European menagerie seems highly vulnerable, and its demise foreshadowed extinction elsewhere.<
Hadrosaurs don't seem to be cut out well for defense, yet they survived through several tyrannosaurids (_Gorgosaurus_, _Albertosaurus_, _T. rex_), not to mention other predators. I don't see how the vulnerability of an extinct animal can be stated, and then used as a reason for extintion.
Did this make sense? I'm tired, and getting ready to head to Utah for the summer...
Peace,
Rob


Student of Geology
Northern Arizona University
P.O. Box 20840
Flagstaff, Az. 86011
AIM: TarryAGoat
http://www.geocities.com/elvisimposter/dinopics.html
http://www.cafepress.com/RobsDinos
"A _Coelophysis_ with feathers?"

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