Saarina is tubes-dwelling of unknown organisms known from siliciclastic

Siliciclastic

Siliciclastic rocks are clastic noncarbonate sedimentary rocks that are almost exclusively silica-bearing, either as forms of quartz or other silicate minerals. All siliciclastic rocks are formed by inorganic processes, or deposited through some mechanical process, such as stream deposits that are...

 deposits of the late Vendian (Ediacaran) and lowest Cambrian

Cambrian

The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...

 of the Russian Platform. It was organic thin-walled segmented tubes constructed as funnels densely enclosed each other. These initially organic tubes have remained thanks to the thinnest superficial piritization at an early stage of decomposition.

Three Saarina species has been described. Saarina tenera from the Rovno regional stage, lowermost Cambrian (Nemakit-Daldynian). Saarina kirsanovi and S. juliae from the Redkin regional stage, Upper Vendian (Ediacaran), aged around .