are there other planets apart from pluto that were planets but were demoted to dwarf planets? and thanks for answering

Question: are there other planets apart from pluto that were planets but were demoted to dwarf planets? and thanks for answering all my questions:)
- Keywords:
  discovery,
  planet,
  pluto
Asked by FelicityP to Helen, Hugh, Julian on 20 Nov 2014.
- Julian Onions answered on 20 Nov 2014:
  
  Well sort of. The asteroid Ceres – which is now a dwarf planet – when it was originally discovered was named a planet. Then they started to find lots more asteroids so it was demoted from being a planet to an asteroid.
  
  Now a similar thing has happened to Pluto, so Pluto was downgraded to a dwarf planet, but Ceres upgraded to a dwarf planet. So it’s had an interesting history!
- Helen Johnson answered on 21 Nov 2014:
  
  I actually didn’t know Ceres was once classified as a planet! Cool!
  For dwarf planets to become planets they need to have cleared their orbit of other space debris, and to have enough gravity to pull themselves into a sphere. I’m not sure what the criteria is for something being an asteroid over a dwarf planet though.
  
  Aha! Ok so apparently a dwarf planet has to be spherical (the gravity controlling its shape part of the planet criteria), but an asteroid can be as lumpy and bumpy as you like.

Question: are there other planets apart from pluto that were planets but were demoted to dwarf planets? and thanks for answering all my questions:)