The Stephanian is a stage in the regional stratigraphy of northwest Europe with an age between roughly 307.5[1] and 299 Ma (million years ago).
The uppermost units of the Coal Measures of England and Wales are probably of Stephanian age, though the larger part of this formation is referred to the earlier Westphalian.
The early part of the Stephanian is difficult to recognize in much of Europe, due to sediment hiatuses or a transition from coal to unfossiliferous red beds.
This issue is most apparent in the Lorraine-Saar-Nahe Basin of France and Germany, where a long hiatus occupies several million years between the Westphalian D and Stephanian A substages.
Other studies disagree with this approach, instead defining the Westphalian-Stephanian boundary at a major transition of plant faunas prior to the hiatus.