Type of Animal

Armour-Plated Fish


10-12 metres


5-6 tonnes

Dunkleosteus was a large, armoured fish that lived roughly 380-360 million years ago. It was carnivorous, and the top predator in the Devonian seas. Its name means 'Dr.David Dunkles Bones'.

Walking with Dinosaurs

Dunkleosteus didn't feature in the main series of Walking with Dinosaurs.


Dunkleosteus featured in Sea Monsters. Nigel found one in the Fifth Most Deadly Sea. He went up against it inside a diving cage, and the Dunkleosteus continually bashed its armoured head against the cage, but it held - due to being of a purpose built spherical design made to deflect head on attacks, much like a dog trying to grip a well made football.

Dunkleosteus was a 10-12 metre long, 20-30 tonnes Apex Marine Carnivore. It was the biggest of its kind.

Dunkleosteus lived during the Devonian Period, from 380-360 Million Years Ago, being one of the widly successful Placoderm (plated skin) Fish Order. Dunkleosteus is known to have been a clear Apex Predator, feeding on literally everything it could get its jaws on - including smaller individuals of its own kind. Cannibalism would have been a trait of this monstrous fish, as is shown on the episode as an Adult devours a scavenging juvenile in a sudden attack surprising Nigel Marven. Dunkleosteus interestingly did not possess any teeth at all - instead, horrifying jaw bone extensions evolved to form a deadly pair of savagely shaped shears that would close with awesome force to trap and indeed decapitate prey in its vice like jaws.

Dunkleosteus, as with all Placoderms, seem to have been wiped out at the end of the Devonian Period along with numerous fish families that had once been successful in past periods. The Devonian Period was indeed the so called 'Age of Fishes', and it ended with a great extinction that removed many older, more primitive types of Fish. It appears that theentire Order of the Placoderms, which had appeared at 90 million years before this extinction, were wiped out wholesale (though 90 million years sounds long to many, for a Fish Order this a surprisingly short time for an entire order to come and go - the Order of Chondrichthyes, the Sharks, by comparison are still with us in the Present Day even after over 400 Million Years) As it happens, it is argued that though Sharks would definately have been easy prey and easily on the menu for Dunkleosteus and similar Placoderm predators related to it. The placoderms died out as a result of the Late-Devonian mass extinction.