The Emsian is one of three faunal stages in the Early Devonian Epoch.

[8] The GSSP is located in the Zinzil'ban Gorge in the Kitab State Geological Reserve of Uzbekistan, 35 centimetres (14 in) above the contact with the Madmon Formation.

In North America the Emsian Stage is represented by Sawkill or Sawkillian time.

During this period, earliest known agoniatitid ammonoid fossils began appearing within this stage after first appearing in previous stage and began to evolutionarily radiate within this stage, in which a new ammonoid order Goniatitida rises in the end of Zlichovian stage (Siberian representation; corresponds to early Eifelian and after the end of Early Devonian, before 391.9 mya).

[9][10] Later agoniatitid ammonoids would die out in the Taghanic event in the upper middle Givetian.