Sam tapped a picture card near the chalk dinosaur trail. “But how can anyone know a dinosaur’s shape or color,” Sam asked, “if no people saw one?” Mina leaned in with her magnifying glass. “Did they just guess the stripes?”

Grandma Noor knelt beside them on the warm kitchen tiles. “Bones, tracks, teeth, feathers, and nests give real clues,” Grandma Noor said. She touched Sam’s notebook gently. “Some parts scientists know well. Some parts are smart guesses, and guesses can change when new evidence shows up.”