Now time to get down to business. Take a look below at the tragopan, which uses it wattles and calls to attract mates.
Now, who's to say that dinosaurs or prehistoric reptiles, birds, etc, didn't possess any fanciful wattles, feathers, scales, throat pouches, or any other form of display structure like this? Some people say there's no evidence of it, but once it gets down to it, you can't find skeletal evidence of a chicken's wattle, or a peafowl's train. There might be some tidbits of skeletal evidence (for example, the pygostyle in Nomingia gobiensis), but not much. Tragopans do not have preserved wattles in their skeletons, either. And take a look at the common peafowl or the argus pheasant. Non-avian dinosaurs and prehistoric birds alike could attract mates like this, using the eyespots to draw attention to their brightly coloured heads.
The classic blue-tongued skink. We also don't know what animals could have done to defend themselves from predators from just their skeletons. Anyone finding a skeleton of a skink probably won't assume it shows its blue tongue to warn predators. A skunk's skeleton wouldn't show it does a handstand and sprays its opponent with smelly musk; a possum's skeleton won't show it plays dead.
Now, I'm not trying to say we need to make all prehistoric creatures colourful and vibrant and always full of life. Some animals are drab. Elephants, rhinos, many birds, many reptiles, etc. Animals are lazy. Cats, sloths, the like. Some animals just run from predators, like gazelles. But that doesn't mean every piece has to be drab (though some lazy dinosaurs would be nice) and it doesn't mean every piece has to be colourful. An equal balance is nice.