Friday, February 17, 2012


Cephalaspis (seff-uh-LAS-pis) was a bizarre-looking fish that lived in the early Devonian period in fresh water streams and estuaries. It had a horseshoe-shaped headshield, which it could have used for protection or for digging up prey. It probably dug up worms and other burrowing creatures to eat. There were also sensory organs on this headshield. 

Cephalaspis could grow to about one foot long, about the size of a trout. The headshield probably would have slowed Cephalaspis down, because carrying around a heavy shield would be hard to do, even in water, especially for a small fish. Cephalaspis certainly wasn't very fast, so it probably would have relied on the tough head shield for defense. 

©Copyright 2008 by Mike Viney

Cephalaspis had two fins right behind the headshield, and also a long, powerful tail with what looks to me like muscle bands, similar to those on a lancelet. They were probably bottom dwellers, hiding among rocks and debris like modern catfish, sturgeon, and stingrays. 

Most fossils of armored fish only preserve the bony headshield, but in the case of Cephalaspis many fossils also reveal the tail. 

Cephaslaspis was a jawless fish, so it probably had to eat very small prey. But with its bony headshield, it still could have been a formidable hunter of these tiny creatures. It could easily dig up these tiny burrowers with its head and then suck them in quickly, like a modern angel shark. 

Cephalaspis probably had a similar lifestyle to Bothriolepis, a bizarre placoderm from the late Devonian.



  1. Is there any way to rule out some buoyant structure which might have offset the ballast of the headshield?

  2. Wow... I was a huge fan of dinosaurs when I was younger, but to that extent, AND with creatures from even earlier? That's a special gift.
    My name/online alias is Clockwork, Clocky for short. Me & two friends of mine, Sigma & DF, are working on making an online RPG, something like "Pokemon meets Prehistory, plus some magic thrown in for fun". We've come up with almost 400 different magically-infused extinct organisms. That includes 150+ post-dinosaurian animals (plus a tree) & 200 dinosaurs or other animals from the same time period. Unfortunately, we've had only 30 creatures from before the Triassic so far, using up the obvious choices, like Pikaia, Meganeura, & Dunkleosteus. Now, having looked through this blog, I have a few dozen ideas & the beginnings of countless others running through my head, let alone what DF &, especially, Sig (he REALLY likes his invertebrates) will come up with when they have a look. So I know I speak for all of the Cratalis staff when I say we look forwards to more!