This multidirectional arrangement of the vertebral spines parallels that in mammals today, but it was unheard of in Devonian tetrapods until we studied Ichthyostega.

• 脊柱上棘的多方向排列与现生哺乳动物成对照，但在我们研究鱼石螈之前，并未在其他泥盆纪四足动物身上听说过。