Order: Haptorida print
- Cellular forms
- Domain: Eukaryota
- Kingdom: Animalia
- Subkingdom: Monocytozoa or Protozoa
- Phyllum: Ciliophora
- Class: Litostomatea
- Order: Haptorida
- Family: Mesodiniidae
- Family: Didiniidae
- Family: Enchelyidae
- Family: Fuscheriidae
- Homalozoonidae
- Family: Lacrymariidae
- Pseudotrachelocercidae
- Family: Spathidiidae
- Family: Tracheliidae
- Family: Trachelophyllidae
- Family: Enchelyodontidae