Some Dinos Thrived toward K-T Event, Others Faltered

Galvasean

It looks to me as if things were 'business as usual' with some dinosaur groups doing better than others right up to the great extinction event.

Brusatte and co-authors tracked disparity trends among ankylosaurs, sauropods, hadrosauroids, ceratopsids, pachycephalosaurids, tyrannosauroids and non-avian coelurosaurs during the last 12 million years of the Cretaceous (from the Late Campanian age to the Maastrichtian). There was no simple pattern that held true for all dinosaurs—some groups stayed the same while others declined. The heavily armored ankylosaurs, dome-headed pachycephalosaurs, formidable tyrannosaurs and small, feathery coelurosaurs didn’t seem to show any major changes in disparity over this span. And the massive, long-necked sauropods showed a very slight increase in disparity from the Campanian to the Maastrichtian. Both locally and globally, these dinosaur groups were not dwindling away.

The shovel-beaked hadrosaurs and horned ceratopsids showed different trends. Horned dinosaurs suffered a significant drop in disparity between the Campanian and the Maastrichtian, at least partially attributable to the disappearance of an entire ceratopsid subgroup. During the Campanian, both centrosaurines (like Centrosaurus) and chasmosaurines (like Chasmosaurus) roamed North America, but by the Maastrichtian, only the chasmosaurines were left. And while hadrosaur disparity dipped slightly from a global perspective, the pattern differed between continents. In Asia, hadrosaurs appear to show very slight increases in disparity, but North American hadrosaurs suffered a sharp decline across the 12-million-year study range. What was true for North American dinosaurs was not necessarily true for the rest of the world.

http://blogs.smithsonianmag.com/dinosaur/2012/05/new-wrinkle-to-the-story-of-the-last-dinosaurs/

Adam Khor

But I wouldn´t trust these studies much because different kinds of dinosaurs had different habitats as well, and not all of them became fossilized due to the particularities of their respective habitats...

Galvasean

Well, now is your chance to take it up with them directly. They are doing a live chat tomorrow and you can Twitter them questions/comments:
http://chasmosaurs.blogspot.com/2012/05/thursday-live-chat-about-late.html

Galvasean

Did anybody watch the chat?
I was in work so missed it