Its lower boundary is defined as the first appearance datum of the graptolite species Nemagraptus gracilis around 458.2 million years ago.
[7] The name Sandbian is derived from the village Södra Sandby (Lund Municipality, Skåne County, Sweden).
[8] The GSSP of the Sandbian is the Fågelsång section (55°42′49″N 13°19′32″E / 55.7137°N 13.3255°E / 55.7137; 13.3255) at Sularp Brook, east of Lund (Skåne, Sweden).
The lower boundary of the Sandbian is defined as the first appearance datum of graptolite species Nemagraptus gracilis in that section.
This article related to the Ordovician period is a stub.