The classification of countable ultrahomogeneous antimatroids of convex dimension two, using a unique realization result for finite antimatroids was discussed. It was proved that any two countable ultrahomogeneous antimatroids with the same age are isomorphic. The characterization of nonatomic ultrahomogeneous antimatroids was achieved using a lot of amalgamation work.SCOPUS: ar.jinfo:eu-repo/semantics/publishe