Don Lessem is a stickler for accuracy. His company, Dino Don, fields 205 rentable robots, mostly dinosaurs, in zoos, aquariums, and museums worldwide. He also sells them. They're full-size--a 120-foot-long Argentinosaurus is heading to the Leipzig Zoo in Germany--because "part of what's cool about our dinosaurs is how big they are," he says. And you won't see any nonsense like a Hadrosaurus with webbed feet. "If you're a 6-year-old or a scientist--the two most knowledgeable groups of people--you know that is wrong," he says.

The former journalist fell hard for the big beasts in 1988, while reporting for The Boston Globe. He launched his company in 1993 with a traveling exhibit that corrected inaccuracies in the movie Jurassic Park, on which he had served as dinosaur adviser. For years, Lessem created shows featuring casts made from dinosaur skeletons, augmented by models and fossils. The $5 million, six-­employee shop operates out of his Media, Pennsylvania, home (called Troodon Manor, after the "smartest" dinosaur).

Long disdainful of existing models, Lessem decided to build his own--in Zigong, China, a hub of the robotic dinosaur industry. He provided the artisans with photos of fossils with imprinted skin patterns, and illustrations of realistic poses. Professional paleontologists oversee production.

He made his first sale in 2019, to the Bronx Zoo, and then invited 20 directors from other zoos to see the exhibit, at his expense. Ten came. Eight ordered. The company has already booked more than 40 clients for 2021, when Lessem anticipates revenue will approach $15 million.