Ramblings & questions

["Dino Rampage" <dino_rampage@hotmail.com>]

1) I understand now that the majority of restorations & reconstructions of 
"Oviraptor philoceratops" are actually of Citipati sp. So what did the 
'real' O. philoceratops look like? Was its cranial ornamentation any 
different? And what about C. osmolskae? What sort of headgear did it flaunt?

2) Is it generally accepted that Elmisaurus was also present in North 
America?

3) Basically, I feel that the whole hadrosaur survival issue has been blown 
out of proportion. True, there may have been certain populations of 
hadrosaurs, both lambeosaurine & hadrosaurine, that may have been 
ill-equipped to deal with the appearance of Tyrannosaurus. But overall, I 
believe that hadrosaurs of Lancian age were generally more than able to 
survive alongside Tyrannosaurus. True, they didn't have formidable armour/ 
weapons like the ankylosaurs or ceratopsians, but it is possible that they 
may have had certain advantages of their own. Who knows, maybe hadrosaurs 
were the most alert herbivores? Heightened senses, like slightly better 
vision, or better hearing? And maybe hadrosaurs frequently associated in 
mised-species herds, just like grazers do so in Africa today eg. wildebeest 
& zebra, zebra & topi, zebra & ostrich or giraffe, grant's & thomson's 
gazelle, baboon & impala etc. And maybe their flight distance in response to 
the presence of predators could have been the greatest as compared to 
ankylosaurs & ceratopsids.

And perhaps due to their heightened senses, they were well-equipped to 
detect the presence of a lurking pack of tyrannosaurs often enough. We have 
to remember that flight is not the only option; in many herbivores the best 
defense is a good offense; instead of flight, sometimes they bunch together, 
snorting & stamping, and generally creating a whole lot of noise. This 
signals to the predator(s): We've seen you, don't bother attacking. Maybe it 
would have been less effective against cursorial predators like 
tyrannosaurs, but if a hadrosaur had to depend on full-fledged flight, 
perhpas it may have been more maneouverable, or perhaps it had more 
endurance than a tyrannosaur. Who knows?

And if cornered, a mature hadrosaur may actually have the weapons to fight 
back. Think of those powerful hind legs. A well-aimed kick could fracture a 
tyrannosaur's ribs or ankle. Or how about those front legs? Perhaps a 
cornered edmontosaur reared up & 'boxed' with its front legs. Remember: the 
tyrannosaur has to inflict enough damage to incapacitate its prey. The prey 
has only to put up a fight that can potentially severely threaten the 
predator's health. True, a crippled tyrannosaur may have pack memebers to 
feed it, as well as depending more heavily on scavenging, but i think the 
odds of it surviving for long would be slim. Remember Big Al the Allosaurus?

And on nesting grounds, perhaps extra vigilance helped lessen the risk of 
attacks. Mobbing behaviour perhaps? In any case I don't think hadrosaur 
mothers abandoned their nests so easily: Can you imagine if an entire herd 
fled at the attack of a tyrannosaur, thus leaving the entire nesting ground 
open to nest-raiders? And if that were the case, eventually all the 
nest-raiders in the area would wise up to the fact that attacking 
tyrannosaur = no protective parents = all-you-can-eat buffet. I don't think 
any species can take such predatory pressure for long, even for an 
R-strategist.

In any case, it is foolhardy to claim that lambeosaurines were less 
well-adapted to tyrannosaurus predation than hadrosaurines on the basis of 
leg ratios alone. True, perhaps lambeosaurines may have been slower, but who 
knows? Maybe they could turn more quickly, & thus use a series of jinks & 
turns to dodge a pursuing tyrannosaur. Or perhaps they were more aggressive 
at defending themselves. Zebra for example, are cursorial animals, and the 
mainstay of the diet of lions & spotted hyaenas. But the harem stallion is 
fiercely protective of his mares & foals, & there are many cases of lions & 
hyaenas being trampled, kicked & bitten. The thing is, we tend to look at 
the predators as the lords of their realm, supreme over the herbivores. But 
the herbivores are not totally defenceless. Heightened senses, vigilance, 
mixed-species association, & offensive threats all give them an occasional 
edge over the predators. We must remember that the majority of hunts end in 
failure; thus, the herbivores must be doing something right. Tyrannosaurus 
was not a supreme omnipotent carnivore; it was just another predator, eking 
out a living by feeding off the vast herds of hadrosaurs, ceratopsids & 
ankylosaurs.

The truth is, we will never know whether lambeosaurs were really slower than 
hadrosaurines.

4) And by the way, it seems that there is an opinion that Tyrannosaurus rex 
evolved in response to the immigration of titanosaurs into North America. 
May I ask, in what way could the addition of a relatively large sauropod to 
the North American fauna cause a daspletosaur-like tyrannosaurid to evolve 
into T-rex? And how different was the Javelina formation from the Horseshoe 
Canyon? Was it a dry upland environment?

Besides, I have also wondered whether Tyrannosaurus rex was an immigrant 
from Asia. (After all, T. bataar is slightly older) Maybe if this is the 
case, it may have adversely affected the other 'native' tyrannosaurs like 
Albertosaurus, Gorgosaurus & Daspletosaurus. (Due to competition, 
intimidation & maybe even outright predation) How this applies to the 
herbivores I'm not sure, but maybe T-rex had to cope with new prey like 
ceratopsids & nodosaurs.

But I do believe that perhaps certain taxa were indeed wiped out by T-rex. A 
medium-sized ankylosaur like Euoplocephalus to be replaced by the giant 
Ankylosaurus is a sign that something was going on: We must remember that in 
the Lancian, most herbivores were giants & far larger than their earlier 
counterparts: Triceratops & Torosaurus (Ceratopsidae) Ankylosaurus 
(Ankylosauridae), Edmontosaurus & Anatotitan (Hadrosauridae) These were 
hunted by the largest of the tyrannosaurs: Tyrannosaurus. However, I'm not 
convinced that ALL lambeosaurines were doomed to extinction at the jaws of 
Tyrannosaurus.

4) I keep hearing that the asian hadrosaurs of the Tsagayan and Barun Goyot 
are different from those in the Nemegt. What are the exact taxa from all 
these formations? And what do they mean that there was a mass extinction of 
asian hadrosaurs after the tsagayan, only to be replaced by american 
immigrants?

5) Shantungosaurus is Campanian? Then are there any edmontosaurs known from 
the Maastrichtian of Asia? And what is the exact stratigraphy of 
Edmontosaurus? I suppose that E. regalis is Edmontonian, E. annectencs is 
Lancian. What about E. saskatchewanensis then? And what about hadrosaur 
remains from maryland & alabama being identified as e. regalis? (across the 
western interior seaway???)

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