Ah. We already have a topic about this.
But that is one of the very reasons why I don't like VI very much. There's plotholes you can drive a giant SEMI through.
If Doc was THE lone dinosaur, then he'd be so much older than Grandpa Longneck...it's unthinkable. NO ONE in LBT can be older than Grandpa Longneck...except slightly.
The tail whip is because he's a Diplodocous (sp?). Scientists believe that they did use their tails as whips, since they were so much more flexible than other sauropods.
And, as another statement that was mentioned, it would be a title handed down from generation to generation, like the Dread Pirate Roberts in The Princess Bride.