The vertebrate jaw is thought to have evolved through developmental modification of the mandibular arch. An extant jawless vertebrate, the lamprey, possesses a structure called “velum”—a mandibular arch derivative—in addition to the oral apparatus. This leads us to assess the velum's possible contribution to the evolution of jaws.

中文翻译：

---

七鳃鳗的发育及其对脊椎动物颌骨进化的影响。

脊椎动物的颌骨被认为是通过下颌弓的发育改变而进化的。现存的无颌脊椎动物七鳃鳗除了口腔器官外，还拥有一种叫做“velum”的结构——一种下颌弓的衍生物。这使我们评估了软膜对颌骨进化的可能贡献。