Today wrestling ins't only olympic or folsktyle. According to FILA Wrestling, the anciest martial art today is :

Olympic Wrestling (Freestyle and Greco-Roman)
Grappling No-Gi
Grappling Gi
Combat Grappling
Pankration
Beach Wrestling
Belt Wrestling
Traditional Wrestling
(Folkstyle Wrestling, Catch Wrestling, Luta Livre Esportiva, Mongolian Wrestling, Gouren....)