The Sandbian is the first stage of the Upper Ordovician. It follows the Darriwilian and is succeeded by the Katian. Its lower boundary is defined as the first appearance datum of the graptolite species Nemagraptus gracilis around million years ago. The Sandbian lasted for about 5.4 million years until the beginning of the Katian around million years ago.
via Wikipedia infobox
The Sandbian is the first stage of the Upper Ordovician. It follows the Darriwilian and is succeeded by the Katian. Its lower boundary is defined as the first appearance datum of the graptolite species Nemagraptus gracilis around million years ago. The Sandbian lasted for about 5.4 million years until the beginning of the Katian around million years ago.
==Naming== The name Sandbian is derived from the village Södra Sandby (Lund Municipality, Skåne County, Sweden). The name was proposed in 2006.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).