Luck runs out

According to recent reports, scientists contend that dinosaurs were able to rule the earth (for a while anyway) because their biggest - as in main - rivals were wiped out by a major event, perhaps climate change, perhaps a meterorite strike. The competition was a group of reptiles called crurotarsans, like today's crocodiles but bigger and, supposedly, resembling dinosaurs. Scientiests suggest the crurotarsans fared better than earlier dinosaurs because the dinosaurs walked on two legs - and could have been warm-blooded. Hmmm. Seems that what we know about dinosaurs keeps changing. And even what they looked like might have been different to common belief: I read somewhere that a man and his son had put together the bones from a chicken carcass, using all the bones, and the resulting frame looked nothing like a chicken. So what guarantee is there that people reassembling dinosaurs bones get it right?