List two structures found in a synovial joint that are
not found in other joints.

Articular discs or menisci, Articular fat pads

Explanation:

Articular discs or menisci - the fibrocartilage pads between opposing surfaces in a joint.

Articular fat pads - adipose tissue pads that protect the articular cartilage, as seen in the infrapatellar fat pad in the knee.

I hope this was helpful, let me know if its correct :)

Tienen una capa de cartílago hialino que cubre las superficies articulares de los elementos esqueléticos

Presencia de una capa articular consistente en una membrana sinovial interna y una membrana fibrosa externa.

Explanation:

Las articulaciones sinoviales son conexiones entre el componente esqueletico en la que los elementos implicados se encuentran separados por una estrecha cavidad articular