Dinosaurs were a superorder of reptiles that existed millions of years ago. 60 million years ago, nearly all species of dinosaurs became extinct, except for the line that had led to the first birds. Warm-blooded vertebrates without fur or feathers did not survive what appears to be a very cold period following a meteor strike on the Earth, thus ending the non-avian dinosaurs species. The most famous dinosaurs are Tyrannosaurus rex, Triceratops, Stegosaurus, and Diplodocus amongst others. Grandpa Smurf seems to be quite knowledgeable about these animals.
In "Future Smurfed", a baby T-Rex was found by the Smurflings which they named Little Thunder. The baby came to be when Lord Balthazar used Father Time's sickle to open a hole in the fabric of time which led into the ancient past. Little Thunder eventually became sick in the present so the Smurfs sought out Father Time and rescued him from Balthazar's castle. Father Time then sent Little Thunder back to his own time.
A Triceratops named Crinkles was a main dinosaur character in the Season 9 episode "The Smurfs That Time Forgot" and was the last of the dinosaurs due to having escaped extinction by being frozen in ice. He was later taken back to his own time with the aid of the Time Scrolls. Other dinosaurs and the earliest birds were also encountered by the Smurfs during their time travel adventures.
In the comic book story "The Smurfosaures", Paleontologist Smurf and Nosey Smurf discover a dinosaur skeleton with two eggs. One of the eggs hatched, a harmless little Brachiosaurus comes out and meets them.