There was an episode that revolved around the Hidden Canyon, which is a place that had a special fruit growing that repelled sharpteeth. I believe it was called The Hidden Canyon.
As for the supposed cameo, I have my doubts that it's Pterano and Petrie's dad. I think they're just a couple of other pteranodons. It's common for LBT to use similiar designs for characters of the same species. Look at Littlefoot and Ali, or Petrie and his siblings. Ali looks similar to a Littlefoot recolor (at least in LBT 4), and Petrie's siblings look like recolors of him. Then there's Ducky and her sisters, and they also look like recolors of her.
So just because that pteranodon looks like Pterano doesn't mean that it's actually him.