bashkirian stage造句

The genus ranges from the Bashkirian stage of the Carboniferous to the early Asselian stage of the Permian.
The upper part of the ( regionally defined ) Namurian stage corresponds to the ( internationally used ) Bashkirian stage whilst the lower part is assigned to the preceding Serpukhovian stage.
The ( regionally defined ) Westphalian stage corresponds to the upper part of the ( internationally used ) Bashkirian stage together with the whole of the series reflecting the stage's earlier status.
It's difficult to find bashkirian stage in a sentence. 用bashkirian stage造句挺难的