Dunkleosteus, a formidable fish, dominated prehistoric oceans during the Late Devonian period (358 to 382 million years ago). This massive armored creature, belonging to an extinct group of fish called placoderms, was characterized by thick bony plates covering its head and thorax. With some species, like Dunkleosteus terrelli, reaching lengths of up to 10 meters (33 feet), it was a powerful presence in the marine environment.
What Dunkleosteus Ate
Dunkleosteus was an apex predator in the Devonian seas. Its diet consisted of various marine animals, including early sharks, other armored placoderms, and large invertebrates like ammonites. The powerful bite of Dunkleosteus allowed it to tackle prey that other contemporary predators could not.
Fossil evidence suggests that the diet of Dunkleosteus shifted as it matured. While juveniles might have consumed softer-bodied animals, adults were capable of crushing through hard shells and bony armor. Evidence of cannibalism also exists, with bite marks matching Dunkleosteus’s jaws found on the bones of its own kind. This broad diet solidified its position as a highly effective predator.
How Dunkleosteus Hunted and Fed
Dunkleosteus possessed a unique jaw structure, featuring sharp, bony plates instead of traditional teeth. These plates functioned like self-sharpening shears, allowing the fish to slice and crush prey. Its powerful jaw muscles enabled a rapid, forceful bite, estimated to be among the strongest of any fish, living or extinct. The bite force could reach up to 8,000 pounds per square inch at the tip of its “fangs,” comparable to modern crocodiles and some sharks.
The mechanics of its jaw opening were highly efficient; Dunkleosteus could open its mouth in as little as 20 milliseconds. This rapid movement created a suction effect, pulling prey into its mouth before the powerful jaws clamped down. This combination of quick suction and immense crushing power allowed Dunkleosteus to capture and fragment even heavily armored or fast-moving prey. While its heavy armor might suggest slow movement, some evidence indicates it was fast enough to pursue swift prey like early sharks.
Uncovering the Evidence
Our understanding of Dunkleosteus’s diet and feeding habits comes primarily from fossil evidence. Paleontologists analyze preserved jaw structures, which reveal the unique bony plates and their operational mechanics.
Further clues come from bite marks on fossils of other ancient marine animals, including other Dunkleosteus specimens. These marks often match the distinct shape and force of Dunkleosteus’s jaws, indicating successful attacks. Fossilized regurgitated bone masses, known as boluses, have also been found with Dunkleosteus fossils. These boluses contain undigested fish bones, suggesting Dunkleosteus would swallow prey whole and later regurgitate indigestible parts.