亚兰达甲鱼（属名：Arandaspis prionotolepis）又称阿兰达鱼或阿兰达甲鱼，是一种生存于奥陶纪早期的无颚鱼类，大约在4亿8000万至4亿7000万年前。亚兰达甲鱼是已知最古老的脊椎动物。

它的化石于1959年在澳大利亚爱丽斯泉被发现，但是直到1960年代末才发现牠们是有史以来最古老的脊椎动物。亚兰达甲鱼这个名称是根据当地的澳大利亚原住民部落亚兰达来命名的。

亚兰达甲鱼大约15厘米（5.9英寸）长，拥有流线型的身体，外部则以硬甲来包覆。亚兰达甲鱼并没有鳍，所以是靠着尾巴左右摆动来前进，因此牠们的游泳方式很可能与现代的蝌蚪一样

Arandaspis prionotolepis is an extinct species of jawless fish that lived in the Ordovician period, about 480 to 470 million years ago. Its remains were found in Alice Springs, Australia in 1959, but it was not determined that they were the oldest known vertebrates until the late 1960s. Arandaspis is named after a local Aboriginal tribe, the Aranda (now currently called Arrernte).