Kentrosaurus is famous for the gradual transition of plates to spikes along its back. Often seen as basal in the stegosaurid family, recently it has been found to be a derived relative of Stegosaurus.Edit
Earth Dinosaurs are from the Thyreophora group, which includes stegosaurians and ankylosaurians (Ankylosauridae, Nodosauridae, "polacanths"). They are resistant against Lightning Moves, but weak against Grass Moves, and their Move Cards are strong against Lightning Dinosaurs and weak againstGrass Dinosaurs. In the anime, Earth Dinosaur cards can be activated by stone, dirt, rock, or any other form of "earth".
Their Move Cards often involve the use of sharp, glowing, purple crystals, or the ground around your opponent. Their TCG abilities are varying, but typically involve letting them stay in play if they lose, but a common theme is that most work either best or only during your opponent's turn while you're on the defensive.