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Re: Massive Dinosaur Graveyard Discovered in Spain



On Dec 11, 2007 5:48 PM, Ralph Miller <ralph.miller@alumni.usc.edu> wrote:

«70 million year old fossils of titanosaurs, ankylosaurs, _Rhabdodon_, and
two theropods - including a 1.8 meter long dromaeosaur -- have been found
where a high speed rail link was being installed near the city of Cuenca in
Eastern Spain. There are thousands of fossils, most of which are turtles and
crocodiles, and they may represent the largest and most diverse dinosaur
fossil assemblage in Europe.  Bones from at least three types of titanosaur
have been found at the site so far, and these fossils include limb bones,
ribs, osteoderms and skull material.  See
http://news.nationalgeographic.com/news/2007/12/071210-dinosaur-grave.html.
Fossils in the path of the rail line have been removed for study, and more
excavations will be conducted in the vicinity next spring.»

>From the news piece:

«...an ankylosaur, a heavily built, squat plant-eater with a big bony
club on the end of its tail for whacking predators...»

I've heard praise given to NG's fact checking crew, and though I can
understand the confusion, I can't but help noting that the description
fits ankylosaurid better. Polacanthid/nodosaurid would be more
probable if my ankylosaurian paleobiogeography doesn't fail me (or
even, given the latent Gondwanan connection some *Minmi* relatives)

«Many experts believe their sudden extinction during the so-called K-T
event (or Cretaceous-Tertiary event) was foreshadowed by a steady
decline in dinosaur diversity, until a massive meteorite strike
delivered a final death blow. The newfound fossil cache appears to
contradict that theory, Sanz said. "This site seems to indicate, as
some [other] scientists have suggested, that dinosaurs were at their
maximum level of diversity during the K-T biotic crisis," Sanz said.
He pointed out, however, that the fossils don't represent the very
last of Europe's dinos, since the remains date to some four million
years before the extinction event.»

"Seems like a lot of work though" to try and make sure one had all
pertinent K-Pg scoured for relevant fossils to do a significant
statistical analysis ;-)
If that work that places Antarctic glacial episodes in the Late
Cretaceous ( http://dml.cmnh.org/2004Mar/msg00000.html ) still holds,
first one can't expect all that much sediment being available for
prospection now what with rivers being constantly swept off their base
levels then, and second one could take those events to somewhat
parallel in abiotic influences what happened in the Quaternary. So
basically to shoulder into another thread: the ecosystems at that time
(LK) were already stressed, not to the point there was a marked
decrease in diversity but to the point where a serious shove such as a
bolide impact would destabilize the environment to eventual breakdown.

My two cents
-- 
Renato Santos
http://www.geocities.com/rfvs1983