Just when we thought we knew all about dinosaurs, a new exhibit rolls into The Nat to share a whole new cast of characters we’ve never heard of before. See, it turns out, all the dinosaur species we grew up obsessing over — brontosaurus, triceratops, and of course the mighty tyrannosaurus rex —  were only half the story. The Ultimate Dinosaurs exhibit tells the other half.

It starts 250 million years ago, when all the continents on earth were jammed together into a giant land mass called Pangea. All kinds of weird animals got busy evolving into early dinosaurs during that time, which we call the Triassic period.

Then, between 145 and 200 million years ago, Pangea split into two supercontinents: Laurasia split north and Gondwana split south. Laurasia eventually broke up into the continents North America, Europe and Asia. All the big name dinosaurs came from these places, living during this decidedly more famous era called the Jurassic period.

However, there were still dinosaurs on Gondwana, of course, and they comprise all of the skeleton castings featured in Ultimate Dinosaurs, which based off of fossils discovered in places like South America and Africa. Several of the 16 fully articulated skeletons featured in the exhibit actually hail from the triassic, like the tiny eoraptor. Closer in size to a German shepherd than an elephant, its 230 million year old remains were found in Argentina, making it one of the oldest known dinosaurs on record.

By contrast, the wonder of evolution can be seen in one of the exhibit’s youngest dinos — the terrifying 70 million year old Giganotosaurus. At roughly 12 feet tall, this is Gondwana’s answer to the T-Rex, and it looks at least as mean, but with a gnarly ridge down the front of its face. Also found in Argentina, it’s considered the largest carnivorous dinosaur, and possibly the largest predator ever to walk the earth. (That was during the Cretaceous period, 65-140 years ago, for all you trivia buffs).

So, why didn’t we learn about these dinosaurs as kids? Pretty much, because scientists didn’t know about them. Paleontologists have only successfully been digging up dino fossils from the southern hemisphere for the last 20 or 30 years. So if you learned about them in school, you should probably be doing your homework right now instead of reading URBANIST.

Because it’s new science, this the first time these dinosaur bones have ever been shown on the west coast, so nourish the spirit of your inner child and go see them before the exhibit’s closing date, September 4th. If you’re really into it, there will be a paleontologist Nat Talk about it at the museum on March 21st.

Ultimate Dinosaurs is on tour from The Science Museum of Minnesota, originally produced by Toronto’s Royal Ontario Museum.