We have portraits of people in our galleries. But what if you’re a natural science museum? How do you portray a dinosaur?  We talk with Kirk Johnson, Sant Director of the Smithsonian's National Museum of Natural History, about the ways our portrayals of dinosaurs have evolved, from sluggish and lizard-like to warm-blooded, colorful and spry. Then Matthew Carrano, curator of dinosauria, explains how the museum put T. rex into a striking new pose. The trick, he says, is to convey how cool dinosaurs were, without making them seem alien. We also tie in a couple portraits from the National Portrait Gallery's collection: an image of the first person to describe an American dinosaur, and a photograph of the first person to give them the Hollywood treatment. See the portraits we discussed: Joseph Leidy, by Frederick Gutekunst Steven Spielberg, by Gregory Heisler The Nation's T. rex, the Smithsonian's National Museum of Natural History Also recommended: Visions of Lost Worlds: The Paleoart of Jay Matternes, by Matthew T. Carrano and Kirk R. Johnson