Here in the Cave of Discovery (I'm pretty sure that's not what they actually called it), you learn how they made all these magnificent dinosaurs. Turns out, they just carve 'em out of styrofoam and slap fiberglass on top. Oh. That said, they certainly do a better job than I could. Of carving dinosaurs out of stryrofoam. And dipping them in fiberglass. (It's a little disappointing to think about, isn't it? I try not to dwell on my time in the Cave of Discovery.)
