Dinosaur expert creates life-sized dino robots for Philly Zoo

PHILADELPHIA -- Don Lessem doesn't just like dinosaurs, he digs them - literally.

He has excavated dinosaurs in Alaska, China and Mongolia, among other places. Through his work over the last three decades, he's come to be known as "Dino Don," an expert on dinosaurs.

Lessem started his career as a journalist, but rediscovered his childhood passion for dinosaurs in his thirties; traveling the world to find them. He garnered much knowledge from scientists while participating in dinosaur digs across the continents.

He has written 40 books on dinosaurs, most of which are geared towards kids.

Lessem says when depicting dinosaurs, his goal is for them to be as scientifically accurate as possible.

He says kids naturally love dinosaurs, so part of his mission is to capture that excitement.

His attention to dinosaur details led to working with director Steven Spielberg on the 1993 Hollywood blockbuster film, "Jurassic Park." Lessem was a consultant, along with dinosaur scientist Jack Horner, on whom the film's main character is based.

Lessem has even had a dinosaur named after him, called the Lessemsaurus.

About three years ago, Lessem embarked on his latest dinosaur endeavor, becoming President and CEO of Dino Don, Inc., a company which makes life-size robot dinosaurs.

And right now, these dinosaurs can be seen at the Philadelphia Zoo.

Lessem says he wanted to present the dinosaurs in a way that visitors could really feel the awe of how big these animals were when they walked the Earth. He has more plans in the works and says the idea of retiring is bizarre to him.