There are many theories as to why the dinosaurs disappeared about 65 million years. Two of the most popular are the meteor crash in Mexico and/or many nuclear bombs at the same time. Both would have blotted out the sun and created a devastating winter which killed the dinos.
There is evidence that dinosaur skeletons give off radiation, so I lean to the nuclear warfare scenario.
I find it hard to believe that dinosaurs developed into such huge creatures (some weighing 100 tons) without help. We all know that plant size can be increased by gene manipulation. Why not dinosaurs?
Millions of years ago, I can see the Earth as a farm for harvesting these creatures. Maybe, an alien fastfood chain were making "McDinosaur Burgers".
There is evidence that humanoids were around during the dinosaur era. Also, it's highly likely, they hunted dinosaurs like humans hunted elephants years ago.
The hunting ended when the dinosaurs were killed off during an intergalactic war.(Pleiadians vs Reptiles?)
Can you imagine the kind of comedy programs that could have come out of this war? Check out these TV finales.
Maybe, it was cool millions of years ago to kick butt in Dinosaurland, but now all we can do is listen to "Alley Oop" and remember the good old days.
St Johns