半圓三角孔貝

半圓三角孔貝（Trigonotreta semicircularis Shen et al., 2000）是採集於保山市的岩石標本。

基本介紹

• 中文名：半圓三角孔貝
• 外文名：Trigonotreta semicircularis Shen et al., 2000
• 產地：保山市
• 保存單位： 中國科學院南京地質古生物研究所

特徵描述

this species is most similar to spirifer fasciger var.paucicostulata (reed)(angiolini,1995) in terms of its semicircular outline,less pointed umbo and square-shaped cardinal extremitites.however,t.paucicostulata has fascicles of up to 6 costae on the ventral valve.t.lyonsensis archbold & thomas (1986) from the latest asselian-sakmarina lyons group in the carnarvon basin,western australia,is readily distinguishable from the western yunnan species in its transverse outline and acute and alate cardinal extremities.t.stokesi koenig (1825) fiffers from the present species in its more rounded outline and more prominent costae.

主要用途

地層劃分與對比。