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Richardsonellidae 科具有向前伸开明显的面线前支,扇形的头鞍前区,眼叶半圆形, 较大,头鞍锥柱形,系 Raymond(1924)以 Richardsonella 为模式属所建。该科一般被认为限于晚寒武世至早奥陶世早期,分布范围比较广泛,基本上各大洲都有发现。因此, 它对寒武-奥陶系界线的划分与对比很有意义。国内专家近年来在寒武-奥陶系界线剖面工作时,也收集到该科的不少资料。但大都限于华北地区奥陶系冶里组的底部。1986年笔者
The Richardsonellidae branch has a prominent anterior facial line anterior, fan-shaped head saddle anterior, ocular semicircular, larger, head saddle cone, Raymond (1924) to Richardsonella model is built. The family is generally considered to be limited to the Early Cambodian to Early Ordovician early distribution of a wide range, basically found on all continents. Therefore, it is of great significance to the division and contrast of the Cambrian-Ordovician boundary. In recent years, domestic experts in the Cambrian - Ordovician boundary line work, but also collected a lot of information in the section. But most are limited to the bottom of the Ordovician Yeli Formation in North China. 1986 author