No offence, but the dinosaurs could still be millions of years old, just not those specific bones. The whole "every single dinosaur was wiped out at once" thrown about sentence is the biggest pile of shit I've ever heard and beyond un-scientific, yet is spouted with "this is the 100% truth...even though we don't really know". Plenty of other species survived, no doubt many dinosaurs did, too. For all we know dinosaurs were still around a thousand years ago, and tales of monsters/sea devils/behemoths were dinosaurs. No doubt killed/eaten and bones destroyed, leaving no trace.