Kingdom Animalia
Phylum Chordata
Class Osteostraci
Subclass Cornuata
Order Cephalaspidida
Family Cephalaspidae
Genus Cephalaspis
1st Species Cephalaspis lyelli
2nd Species Cephalaspis murchisoni
3rd Species Cephalaspis salweyi
4th Species Cephalaspis dawsoni
Other attributes
Time Range 415-398 mya
Location United Kingdom, Canada, United States of America, Ukraine
Name Meaning Head shield
Physical Dimensions 20 centimeters long
Dietary Classification Carnivore

Cephalaspis is a cephalaspid cephalapsidid jawless fish from the Early Devonian of the United Kingdom, Canada, the United States of America, and Ukraine. It was named in 1843 by Louis Agassiz. It was one of the last jawless fishes to exist, as well as one of the most unique.


Cephalaspis had a build very similar to generic jawless fishes, with a mobile tail, an oval-shaped body, and a toothless mouth. However, it had a few major differences; for example, it had an armored head with eyes positioned very close to each other, and instead of being in the front of its head, its mouth was on the bottom of its head. Its body would have been covered in scaly skin, with bony plates protecting its head.


Cephalaspis was a predator, feeding on small invertebrates by sifting through the seafloor and sucking them up. As well as this, it would sometimes settle for detritus suspended in the water.


Cephalaspis's head shield was used as a defense against predators, since it was a slow swimmer. As well as this, it had sensory organs on the rim of its head, which were used for feeling the sand and mud, detecting any prey in the way. It lived in freshwater streams and estuaries, preferring to feed on the riverbed. In order to hunt, it would move its head from side to side, launching up sand and mud, as well as digging up any worms or crustaceans hiding in the ground.

In popular cultureEdit

Cephalaspis was featured in the 1st episode of the 2005 documentary Walking with Monsters, where it escapes the claws of a marauding Brontoscorpio; as well as this, it was depicted as an anadromous marine fish, migrating into freshwater in order to breed. However, in the show, Cephalaspis was depicted as starting out in the Silurian, while in reality, it started out in the Devonian; as well as this, it was an entirely freshwater fish, and did not live in the seas.

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