The Ustmylian Gorizont ("Ustmylian Horizon") is a Lower Triassic biostratigraphic unit in Western Russia.
It corresponds to the later part of the early Olenekian stage.
Along with the Sludkian Gorizont, the Ustmylian Gorizont is encompassed by the "Wetlugasaurus fauna", named after a capitosaur amphibian index fossil.
[1][2] The Ustmylian is exposed in several svitas (equivalent to geological formations) spread out over a wide area.
[1][3][2] This article about a specific stratigraphic formation in Europe is a stub.