The Fortunian age marks the beginning of the Phanerozoic Eon, the Paleozoic Era, and the Cambrian Period.

Its base is defined as the first appearance of the trace fossil Treptichnus pedum 538.8 million years ago.

The top of the Fortunian which is the base of the Stage 2 of the Cambrian has not been formally defined yet, but will correspond to the appearance of an Archeocyatha species or "Small shelly fossils" approximately 529 million years ago.

[6] The type locality (GSSP) of the Fortunian stage is in Fortune Head, at the northern edge of the Burin Peninsula, Newfoundland, Canada[6] (47°04′34″N 55°49′52″W / 47.0762°N 55.8310°W / 47.0762; -55.8310).

This GSSP coincides with the base of the Terreneuvian series, the Precambrian-Cambrian boundary and the beginning of the Phanerozoic.