If that T-Rex sticking its head out of the glass roof of the Conservatory of Flowers doesn't startle you, there are always some of its monstrous friends inside who may.
Add giant ferns and other plants, you have Plantosaurus Rex, an exhibit that starts 250 million years ago and finishes a mere 65 million years past. It begins as a barren supercontinent broke apart.
"As that happens, a lot of rivers are formed, a lot of lakes are formed, and in general, the earth becomes a lot more humid. As that happens, plants are actually able to evolve. There's a lot more water, a lot more nutrients, there's a lot more competition," said Lau Hodges, the director of operations and exhibits.
Plants develop defense mechanisms. And flowering plants show up at the end of that period. Many of today's flora and fauna have roots to those times and there is a way to verify they existed.
"One of the ways scientists know what dinosaurs ate which plants, which plants were around then, which plants they preferred. There is actually a group of scientists there that study dinosaur poop," said Hodges.
That's probably the first time we've used that word. This show is interactive. Push a button and you'll hear a creature's sound or feel the earth move.
"At the time, a lot of volcanic activity, a lot of plate movement, a lot of lava flowing," said Hodges.
You'll also encounter massive dragonflies and a turtle that's real. And there are wall to wall plants.
It's about a time when new plant forms were emerging and the earth was shifting. You could say the conservatory of flowers has turned this area into Golden Gate Jurassic Park.
Plantosaurus Rex is up into October.