对该时期笔石的生物地理分析表明，洛赫科夫期的笔石具有全球性，而布拉格期的笔石则显示出一定程度的地区性。
A global correlation of the graptolitic strata of this interval is preliminarily proposed , and the biogeographic distribution of Early Devonian graptolite species is discussed in the present paper .
洛赫科夫期