What thing is the same between a trex and triceratops?

Both Tyrannosaurus rex and Triceratops were dinosaurs. They were also very similar in regards to weight, and they were both very formidable to their enemies. Of course, they both had all the basic body parts for a dinosaur, the head, the torso, the four limbs, even though Tyrannosaurus had very small arms, and the tail.