Thanks so much for making this available!!
I gotta say, when I first started reading , I thought it was barely going to be any different than the final version, but reading it all the way through, there are definitely some notable differences. Here are my thoughts!
I actually prefer the final version of the movie, and my biggest reason for that is the difference in Cera's characterization. First, I noticed this script didn't have her parrot her dad's line, "Threehorns never play with longnecks." That moment emphasized that Cera, early in the film, had been raised to become a mini version of her father, prejudices and all. Although we can still tell that about Cera in this earlier script, the film version that has her word-for-word repeat the line particularly accentuates that she's the product of her upbringing (and is probably why "Threehorns never play with longnecks!" is such a memorable line in the first place). Second, I think Cera's overall development arc was done better in the movie. The moment where she goes to cry by herself, which showed the vulnerability she'd been hiding under her anger, was absent from the script. The Cera of the script has a lesser range of emotions altogether. She's almost purely aggressive up until the moment where she comes to save the day in the Sharptooth trap scene, and that made it feel like a pretty sudden turnaround in my opinion.
I also want to bring up the name Thunderfoot. It wasn't news to me that Thunderfoot was Littlefoot's original name, since I'd seen that on a wiki page before. However, I had never thought much about it before reading this script--but seeing it about five times or so on every page of this sure forced me to think about it. Boy, am I glad another dinosaur character had already taken this name! The character types my head conjures up from the names "Thunderfoot" and "Littlefoot" are polar opposites. Littlefoot sounds like a fitting name for a wide-eyed, scrappy young dinosaur, while Thunderfoot gives me the image of a big, strong, maybe even brutish character. Yeah, Thunderfoot would make more sense once the character grows up, but seeing as how we've had fourteen movies now and no one looks like they've aged one day, I don't think there's any danger of Littlefoot outgrowing his name at this rate!
Also...Petrie. The way he was written in this script just leaves me...confused. So he was just going to whistle, not talk, all through the movie? At first, I was thinking the writers were probably just trying to suggest that he was younger than his friends and couldn't talk yet, but in the valley scene, it turns out his mother also just whistles. And I wonder what the purpose was for their "words" being written in parentheses after each whistle. Was that just put there for reference to make writing dialogue between Petrie and the other characters easier? Or was it going to be shown on subtitles or something? Then there's the matter of Petrie's grammar. In the movie, it came across as being just a childlike quirk of his, but this script gives his mom the same grammar problem. I guess in addition to whistling instead of talking, all flyers also have poor grammar. It's like they're supposed to be dumber, more animal-like creatures than the dinosaurs, a scenario which (pun alert) doesn't quite fly with me.
I also prefer Littlefoot's first look at the valley being saved for the very end of the movie. I liked him being able to have that moment with his friends standing right beside him, not with him having to go back and find them. By having the kids run down into the valley immediately after seeing it for the first time, the movie scene was the Gang's singular moment of joyful triumph, the crowning glory waiting at the end of their journey. No one character should have been able to have that moment alone--it needed to be saved until they'd all completed their journey so they could take it in side by side. Maybe nostalgia is blinding me on this part, though...
To wrap this up, I really (really!!) enjoy seeing material like this from behind the scenes of my favorite movies. In the end, though, I'm almost always glad that the final version became what it did. There's a reason movie scripts get revised. What we're looking at here was a work in progress, not some truer, purer version of LBT that was smothered by the one we got. Not to offend anyone who wishes this would've become the final movie, but I prefer the original LBT just the way it is.
Well, on to that Secret of Saurus Rock script now!