陕西南郑梁山中奥陶统的小四齿贝（腕足类）

Tetraodontella(Brachiopoda) from Middle Ordovician at Liangshan of Nanzheng,Southern Shaanxi

研究产自陕西南郑梁山中奥陶统宝塔组小四齿贝（Ｔｅｔｒａｏｄｏｎｔｅｌｌａ）的两个种，即横展小四齿贝（Ｔｅｔｒａｏｄｏｎｔｅｌｌａｔｒａｎｓｖｅｒｓａ）和隆凸小四齿贝（Ｔｅｔｒａｏｄｏｎｔｅｌｌａｉｎｆｌａｔａ）。

The specimens occur in Pagoda Formation of Middle Ordovician.from Liangshan of Nanzheng,Southern Shaanxi.There are two species,one is Tetraodontella transversa,the other is T.inflata.