Pterygoid bone

Ox

• Pterygoid bone are thin plates of bones situated on either side of the posterior nares located over the perpendicular parts of the palatine bones.
• This medial face forms part of the lateral wall of the posterior nares.
• The lateral face meets the palatine and the subsphenoidal process of the sphenoid.
• The extreme upper part of this face forms the pterygoid or vidian canal with the sphenoid.
• The lower extremity is free and forms a curved process the hamulus pterygoideus around which the tendon of the tensor palati is reflected.

Horse

• Shorter and narrower. 
• The lateral surface articulates with the palatine, vomer and sphenoid, concurring with last in the formation of the pterygoid canal.

Dog

• It is wide quadrilateral and short.

Fowl

• It is rod shaped and extends between the rostrum of the sphenoid medially and quadrate bone laterally.