@Pangea  
Actually, I think Pinkie’s a microraptor, but you’re not that far off other than that.

@Evowizard25  
Like there’s a problem with that anyways, right?

@Joshua  
Yep, including the several species of dinosaurs running together that in no way lived in the same time line….Oh my stars, this is the Land Before Time realm.

@Lupin Quill  
I’m going to need you to hide as quickly as you can.
 
………………….Do-you-think-they-saw-us? XD

Let’s see…
 
Rarity: Stegosaurus  
Applejack: Pachycephalosaurus  
Rainbow Dash: Tupuxuara  
Fluttershy: Tyrannosaurus with wings?  
Twilight Sparkle: Triceratops  
Pinkie Pie: Velociraptor  
Spike: Simian
 
Well, those are the first things that came to my mind anyways.

Quick, someone think of dinosaur puns for Rarity, Pinkie and AJ!

Wait a minute… Spike’s a lemur? We’ve DEFINITELY reached Disney’s Dinosaur here folks.

@Bahamut  
It’d make more sense if Spike was an alligator. (I remember that one documentary about dragons that indicated that they were closely related to gators/cros.)
 
And if we went that far, the main six would probably be mouse like rodents.

This is very cool, so… Monkeys evolve into dragons? And dinosaurs devolved into ponys? (I know it’s not true but it would be funny if you think about it)