semisagittate

例句：

1. 1. The fossils found in the cave are of thesemisagittate age.
   洞穴中发现的化石属于半石炭纪时期。
2. 2. Thediscovery of this species in the deep seais a significant contribution to our understanding ofmarine life.
   这种物种在深海的发现对我们理解海洋生物具有重要意义。
3. 3. The studyof semisagittate rocks provides insights into theevolution of marine ecosystems.
   研究半石炭纪岩石为我们提供了关于海洋生态系统演变的见解。