They got outcompeted by the hadrosaurs, which were more developed herbivores

^I'm sure there was more to it, but yeah that's kinda the jist of it,

I agree with AcryAllofan150, but something you should note is that whenever a new hadrosaur species started to be part of the food chain, at least a few species of ankylosaurs and ceratopsians became extinct

^yes. The hadrosaurs murdered many species during their success

Btw, don’t worry about asking too many questions, you learn more when u ask, don’t hesitate to ask

Based AcryAllofan150 real!?!?!?,?,?!!

They fucking died like the others

Aren't Iguanodontids closely related to hadrosaurs? Edit: ChatGPT says Hadrosaurs evolved from Iguanodontids.

^Yep, hadrosaurs evolved from a branch of them.