Depends on the number of articulated bones.
A- Simple joint: (two articulated bones).
B- Composite Joint: (more than two bones within one joint capsule).
Depends on the shape of articular surface.
A- Ball and socket joint: e.g. (shoulder j. Hip i.)
B- Saddle joint: e.g. (Pastern joint of the dog).
C- Hing joint : e.g ( Elbow j. )
D- Condylar joint: e.g. (Mandibular J.).
E- Trochoid joint: e.g. (Atlantoaxial joint).
F- Plane joint: e.g. (joint between the articular processes of vertebrae)
Proximal radio-ulnar joint ossified in horse and ruminants, so it classify as a fibrous joint.
Composite consist of:
1- Common Ligament: