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Ramblings & questions




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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