Re: Bolivian dinosaur trackways

[Tim Donovan <uwrk2@yahoo.com>]

> 
>  it was believed that
> dinosaurs 
> began disappearing gradually from the Jurassic to
> the 
> Cretaceous period,


  To an extent this is still valid. Stegosaurs,
spinosaurs and all/most nontitanosaurid sauropods
apparently disappeared well before the end.



 
> amends the debate about the gradual decline until
> the end 
> of the Cretaceous. We have discovered that in this
> latest 
> period, when massive extinction occurred, the
> existence of 
> the dinosaurs was vast and much more varied than was
> 
> believed until now. The whole collection is right
> there,'' 
> said Meyer. 

   Lockley et al reported the same thing several years
ago based on this evidence. But he indicated that,
although the trackway units are considered of late
Maastrichtian age, their exact age in relation to the
K-T boundary is unknown. They might predate it by 1-2
million years or more, making this a far from perfect
test of gradual extinction.


 
> This 
> animal was represented as a sort of giant, awkward 
> armadillo weighing eight tonnes, but ''the study of
> its 
> tracks in Orko describes for us a saurus much taller
> and 
> thinner, with longer and lighter legs,'' he said.

  An ankylosaur didn't have to be as robust as
A.magniventris to survive in SA.

  
> Also found in Cal Orko were traces of the herbivore 
> sauropods, including the gigantic titanosaurus,
> measuring 
> 25 metres tall and with footprints 70 cm in
> diameter; and 
> the big predators like the theropods, with 35-cm 
> footprints. 

 Not very big compared to T. rex.


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