There's this whole story behind how Dinoland ended up taking it's current form. Like, a real one.
This is from memory, so take all of this with a grain of salt, I may have messed up.
Animal Kingdom was supposed to open with four lands, but ended up with the budget for only three. There was a choice between Beastly Kingdom (fantasy animals) and Dinoland USA.
Dinoland USA wasn't supposed to be half carnival themed. The dig site was supposed to be a bigger focus. They had planned two, big rides; an animatronic heavy prehistoric safari (NOT Dinosaur as it was not meant to be frightening), and a big, wooden rollercoaster through the dig site (called "Excavator ").
In order to make their proposal cheaper while simultaneously shoving in more rides, making it more attractive to the higher-ups, they merged their thrill ride concept with the safari concept (ergo Dinosaur), and made the carnival concept, which came bundled with an excuse to use off-the-shelf rides (though they did customize them a lot a d I think it's worth recognizing that).
Their pitch was then the cheaper and more attraction-filled of the two, and so they got the go ahead.
The whole place was made to be easily torn down, though. Sadly, I guess we'll see how true that is. It wasn't supposed to be permanent, but most people figured they would replace it with more dinosaurs.
(Also, Dinosaur WAS Countdown to Extinction. They changed it to tie into the movie. So blame the animation studio on that one.)
If you're going back soon, I would recommend looking up the backstory of the Dinoland area (the made-up story, not the actual story of making it). It's a lot easier to appreciate the details and what each area is supposed to be if you've done some reading beforehand.
(Maybe even look up the backstory for each Animal Kingdom land, if you're enjoying learning this stuff. Each one has a lot of thought behind it because they're all supposed to feel like a real place.)