Comment on Prenocephale prenes by T-PEKC
Just as I suspected, for some reason you have confused the ornithopod Oryctodromeus with being ornithomimid. A burrowing ornithomimid would have been pretty interesting find.
Here is link to the paper describing Oryctodromeus - rspb.royalsocietypublishing.or…
Also, I mentioned this animal as an "excuse" to portray a denning pachycephalosaur in the description of my deviation: "It’s known that at least some dinosaurs (Oryctodromeus and possibly its closest relatives) had an adaptations of digging and were able to live in dens. Similar adaptations are not known for pachycephalosaurids (as far as my knowledge goes), but many digging/denning animals have no obvious adaptations for such behavior/life style. Here, Prenocephale is using a den to hide from a predator. I won’t go as far as stating the burrow was made by the dinosaur, it may just use already existing one."
Here is link to the paper describing Oryctodromeus - rspb.royalsocietypublishing.or…
Also, I mentioned this animal as an "excuse" to portray a denning pachycephalosaur in the description of my deviation: "It’s known that at least some dinosaurs (Oryctodromeus and possibly its closest relatives) had an adaptations of digging and were able to live in dens. Similar adaptations are not known for pachycephalosaurids (as far as my knowledge goes), but many digging/denning animals have no obvious adaptations for such behavior/life style. Here, Prenocephale is using a den to hide from a predator. I won’t go as far as stating the burrow was made by the dinosaur, it may just use already existing one."
Sorry my fault.
Although the Oryctodromeus; at least partly proves; dinosaurs can burrow Or use underground nests
Although the Oryctodromeus; at least partly proves; dinosaurs can burrow Or use underground nests
Yes, it indeed does! It also disproves that old idea that all non-avian dinosaurs went extinct because even the small ones could not hide in burrows like mammals. 
Agreed & Indeed. 
That leaves another question thought. Why all smaller dinosaurs went extinct either ?
Metabolism ? A disease only effects reptilian animals; like non avian dinosaurs ?
That leaves another question thought. Why all smaller dinosaurs went extinct either ?
Metabolism ? A disease only effects reptilian animals; like non avian dinosaurs ?
I don't think metobolism was deciding factor for their extinction (they were fast growing, most probably endothermic animals). Disease is absolutely out of question - there is no such a selective disease that is spanning over different groups, but affecting only particular taxa. Also disease cannot explain why small non-avian paravians, enantiornithes and alvarezsaurids died out, while birds survived.
My bet is that the deciding factor was ecology and the role animals had in their habitat - non-avian dinosaurs, as dominant terrestrail animals, were at the top of the food-chains and thus they were probably overspecialized and couldn't adjust fast enough to the devastating changes. It is usually the dominant and most specialized groups that get hit hardest during mass extinctions. Taxa with more general diets seem to cope better with severe changes in the environment.
My bet is that the deciding factor was ecology and the role animals had in their habitat - non-avian dinosaurs, as dominant terrestrail animals, were at the top of the food-chains and thus they were probably overspecialized and couldn't adjust fast enough to the devastating changes. It is usually the dominant and most specialized groups that get hit hardest during mass extinctions. Taxa with more general diets seem to cope better with severe changes in the environment.
True; all dinosaurs were\are WarmBlooded. The disease is very old actually; but still used.
Overspecialization could explain the bigger to medium sized dinosaurs; still it doesn't explain why the smallest non-avian dinosaurs went extinct too; I am sure there were several small non-avian dinosaurs at the end of Cretaceous period; who weight under 20 kilograms (I remember most animals who survived the Cretaceous catastrophy were under 25kg of weight). Why they top died out. Maybe hibernation ? Maybe dinosaurs cannot hibernate while some avians can. Maybe dinosaurs were too much 'active' to survive a Catastrophe. If the changes were too fast most small animals can 'suspend' their activities; including eating. Maybe dinosaurs can't.
Overspecialization could explain the bigger to medium sized dinosaurs; still it doesn't explain why the smallest non-avian dinosaurs went extinct too; I am sure there were several small non-avian dinosaurs at the end of Cretaceous period; who weight under 20 kilograms (I remember most animals who survived the Cretaceous catastrophy were under 25kg of weight). Why they top died out. Maybe hibernation ? Maybe dinosaurs cannot hibernate while some avians can. Maybe dinosaurs were too much 'active' to survive a Catastrophe. If the changes were too fast most small animals can 'suspend' their activities; including eating. Maybe dinosaurs can't.