dunkleosteus terrelli


Name: The Bad Dude

Species: Dunkleosteus terrelli

Description: Dunkleosteus is the largest placoderm and the largest Devonian fish, growing up to about 6 meters (20 feet). Like all placoderms, its head is protected by numerous bony plates, which mostly are the only parts that fossilize. The shearing “teeth” are extensions of these plates. Dunkleosteus was an apex predator - and it uses those shears to, well, shear prey. The edges sharpen themselves with each bite, and the bite force gets into the thousands of Newtons. Like several other fish, Dunkleosteus uses suction to get prey into the mouth so it can be sheared.

Location: The Bad Dude lives in a large tank of his own in the Devonian section of the Aquarium.

Fun Facts: We test his bite force over time, to see how it changes with growth. The last test, taken about a month ago, clocked in at 3,243 N!

About the Individual: This is our only Dunkleosteus. He’s approximately 3.4 meters (11 feet) long, a little over half his expected full size. Even at this size, he’s impressive to behold as he passes by the viewing window. He mostly keeps to himself and swims around - though he breaches sometimes, which is quite a sight to the staff on the top deck. We don’t know exactly why. The veterinary team is in the process of checking for parasites, but they don’t think that’s likely.

We feed him chum and meat chunks in edible packages that look like prey (without any significant hard chunks - nobody wants to volunteer to clean up Dunkleosteus vomit). He doesn’t seem to associate people with food and thus doesn’t try to attack the glass often - but just in case, the glass is extremely thick and built to withstand a heavy impact. Thanks to the armored head, he’s shrugged off every bump or nudge thus far.

Yes, he’s named after the Tumblr post. The aquarists didn’t really have a name for him until that post rolled around, they only called him “the Dunkleosteus”.