This is Cephalaspis. She's a peaceful grazer who sucks up algae through her lawless mouth. But she's also developed a tough protective head and thick scales.
— Allen, about Cephalaspis

Cephalaspis ("Head Shield") was a primitive, prehistoric jawless fish the size of a modern trout from the Ordovician to the Silurian period.



Cephalaspis lived during the Silurian and the Late Devonian period from 430-410 million years ago, living alongside Brontoscorpio, Cameroceras, Pterygotus, and other sea creatures.


Being a primitive fish, Cephalaspis was small, about the size of a modern day trout. They were peaceful, grazing fish that sucked up algae through their jawless mouths. They also developed a tough, protective head and thick scales.

These fish also had evolved an early warning system: special sensors on their skin that could detect even the tiniest of vibrations underwater. Their toughened heads had a vital weapon, among the first complex brains, which was much more developed than their scorpion rivals who had no memory at all. It's thanks to these primitive fish that we humans can think and solve problems today.


When breeding season came for these fish, Cephalaspis congregated to head for the one place they could escape the scorpions: fresh water, inland, with their convoy plowing upriver, away from the sea.

They returned to the spawning grounds where they hatched and where their lives began, using memories. But when they were in danger and running from it, with their defensive headgear, Cephalaspis couldn't swim fast for long. They had rest frequently, or soon, they would tire completely.