Other big 3's

[Spinokaprogorgon]

We all know that the big 3 megatheropods are tyrannosaurus, spinosaurus and giganotosaurus. I think ceratopsians will be triceratops, pachyrhinosaurus and styracosaurus. What are the other big 3's?

[Takama]

Brachiosaurus, Apatosaurus, and Diplodocus, are the big three i think of when it comes to Sauropods

[crazy8wizard]

Brachiosaurus, Apatosaurus, and Diplodocus, are the big three i think of when it comes to Sauropods

In terms of popularity, but in terms of overall size, Morrison has bigger sauropods (some of the biggest actually)

[BlueKrono]

I'd say Quetzalcoatlus, Dimorphodon, and Pteranodon. If we're not distinguishing between Brontosaurus and Apatosaurus I'm not going to wade into Pterodactyl/Pteranodon.

Then I'll go Plesiosaurus, Kronosaurus, and Mosasaurus.

[PrimevalRaptor]

Velociraptor, Utahraptor and Deinonychus feels like an easy pick for dromaeosaurs and something else I instantly thought of was stegosaurs where I /feel/ it'd be Stegosaurus, Kentrosaurus and honestly nowadays Miragaia/Dacentrurus? Kentrosaurus definitely has been in a lot of books and also has a ton of toys so I feel it's a trademark guy

[Spinokaprogorgon]

Then I'll go Plesiosaurus, Kronosaurus, and Mosasaurus.

I'd replace plesiosaurus with elasmosaurus and kronosaurus with liopleurodon. 

[Pliosaurking]

Big three armoured dinosaurs
Triceratops
Ankylosaurus
Stegosaurus

Big three "Crocs"
Sarcosuchus
Deinosuchus
Purussaurus

[BlueKrono]

Then I'll go Plesiosaurus, Kronosaurus, and Mosasaurus.

I'd replace plesiosaurus with elasmosaurus and kronosaurus with liopleurodon.

Okay, Liopleurodon yes. Thanks Charlie. But I don't think Elasmosaurus is as well known as the OG.