The turtle is a reptile that lives on all the continents (except Antarctica). It normally has a shell to protect it from predators. In Dinosaur Revolution it is shown in the third episode (Survival Tactics).
The turtle is the first animal showing in the third episode. The turtle is grabbed by a curious Utahraptor but is quickly dropped. The turtle appears later watching a brown Utahraptor pack chasing a herd of Cedarosaurus, only to be kicked out of the way by one of the grey Utahraptors.
It's most likely the turtle is Naomichelys, an extinct turtle that lives with Utahraptor and Cedarosaurus.