Bay Sema from the Dvaravati - time (about 6. to 9. Century A.D.), mainly boundary stones of the U Thong consist period are elegantly verziert with ornamentations at the “neck” and on the “belly” of “shoulders”. Early Ayutthaya boundary stones have a simple “chest” and are out-arranged also otherwise quite meager. Bay Sema from the middle Ayutthaya period are “closely tied” in the “hip” and carry a “Brust-Platte”. In the late Ayutthaya period “eyes” developed in the long run “were crowned” it evenwhich continued into the Rattanakosin period. Under king Mongkut (Rama IV.) the Thammayut medal was created; the Thammayut monks developed a three-dimensional (quadripartite) from the flat Blatt-Form, rather würfelförmigen stone.