teeth in the front of the jaws
spikes on its tail
plates on its back
Correct!
When stegosaurs evolved after Huayangosaurus, they no longer had teeth in the front of their jaws.
Huayangosaurus taibaii
As you can tell from its body plates and tail spikes, Huayangosaurus is related to Stegosaurus. Unlike Stegosaurus, though, this dinosaur had a shorter snout. It lived during the Middle Jurassic in a part of what is now China.