Dinosaur-Deer or Cervisaurus Cornutus (Horned Deer-Lizard) are relatively small, Parasaurolophus-like Hadrosaurs with a single antler instead of a crest. They are 4 meters long.
Dinosaur-Elk or Cervisaurus Maximus (Largest Deer-Lizard) are a different species of Dinosaur-Deer. They have a larger and more ornate antler, brighter colors, and are much bigger, being up to 7.5 meters long.
Size Comparison between the 2 species. You could ride one if you wanted to. Just because you can ride one doesn't mean you should. They're hard to tame and the Dino-Elk's antler would block your view.
