acoelous vertebra

例句：

1. 1. The acoelous vertebrae of the echinoderm are modified to support its body shape.
   棘皮动物的无脊椎动物脊柱被改造来支撑其身体形状。
2. 2.The fossil record of acoelous vertebrates suggests that they evolved from more primitive forms.
   无脊椎动物的化石记录表明，它们起源于更原始的形式。
3. 3. The study of acoelous vertebrates has shed light on the evolution of complex nervous systems.
   研究无脊椎动物的脊柱有助于揭示复杂神经系统的进化过程。