圆口纲脊椎动物

例句：

1. 1. The dinosaurs lived during the age of reptiles, which is now considered to be part of the phylum Chordata.
   恐龙生活在爬行动物的时代，现在被认为是脊索动物门的一部分。
2. 2.The classification of animals into different groups has been a topic of debate among scientists for decades.
   将动物分类为不同的组别是科学家几十年来争论的话题。
3. 3.In the study of evolution, scientists often use the concept of "phylum" to refer to the grouping of organisms based on shared characteristics.
   在进化研究中，科学家们经常使用“门”这一概念，以指代基于共同特征的生物群体。