Why was the Triceratops important?

It was important way back in the day wink wink as it was one of the largest certainly the most dangerous herbivore during the cretaceous period, but I'm guessing that the question isn't importance, but significance. It is one of the most common fossils of any dinosaur- thus any prehistoric animal- found. In fact, it was ten times more common in the era than Tyrannosaurus.