This is a series run by Jim Henson’s daughter Lisa, who seems to be in charge of at least half of all children’s TV programming these days. You can watch the series for free at PBSKids.com or via the PBS Kids app (also free). Neither the site nor the app has ads either. Just make sure to support your local PBS station.
The show is light-hearted and full of factual information about dinosaurs and prehistoric times (assuming you can ignore the fact that the dinosaurs all speak English, ride in a time-traveling locomotive, and are not constantly trying to eat each other).
There are tons of episodes, available in DVD form. A good bet for any kid who’s really into dinosaurs.