Dunkleosteus Terrelli, commonly known as Dunkleosteus, is a huge arthropod shark-like species that lived in the Late Devonian era, roughly 380–358 million years ago. Technically it comprises 10 species, several of whom are the biggest placoderms that have ever existed, but the D.Terrelli is the most common.

David Dunkle was a prominent curator at the Cleveland Museum of Natural History, who first added the Dunkleosteous to the museum’s collection. For his contribution, he was honored by having Dunkleosteus named in his honor in 1956. The name Dunkleosteus translates literally to “Dunkle’s bone” – a combination of David Dunkle’s last name and the Greek word Ostéon, which means “bone.” 

The other parts of the shark’s anatomy are currently unclear because the protective forehead regions of specimens have generally been the ones best preserved and a notable feature of the species.


The largest species, Dunkleosteus Terrelli, is thought to have reached its maximum size and weight, rendering it among the largest placoderms ever known. Darkeosteus might have been a somewhat sluggish but forceful swimmer because of its two-section bony, armored exoskeleton. Dunkleosteus has two pairs of pointed bony plates that created a beak-like framework that held the pair of teeth, notable features that distinguish it from other species. 

Dunkleosteus measured between 15 and 19.6 ft in length, making it larger than the Great White Shark
Dunkleosteus measured between 15 and 19.6 ft in length, making it larger than the Great White Shark

The Dunkleosteus is believed to have measured between 15 and 19.6 ft in length, according to more moderate estimations. The largest species was estimated to have a huge size of 30 ft and weigh around 9,000 lbs according to the most current effort to reconstruct this organism by matching it to contemporary oceanic sharks in related circumstances.


Dunkleosteus was indeed a top predator of its environment and a pelagic fish that roamed the seas of planet Earth. The cranium and jaw muscles were joined by a special linking system that allowed Dunkleosteus to rapidly toggle between opening and closing its jaws. In this manner, the jaw generated a powerful bite force strong enough to shred prey. 

Given the size of its entire jaw, the locations of its teeth in contact, and the power it produces, it could readily puncture and shatter strong shells. As they grew older, their food likewise evolved, moving from small fish, sharks, and other squishy species to armored ammonites, placoderms, as well as other huge, protected animals.


Dunkleosteus survived and thrived in the maritime environment during the Devonian. They are believed to have resided not far from the ocean floor. It has been hypothesized, though, that as they age, the species in this genus migrate to their environment. As the adults traveled far into the sea, the younger Dunkleosteus likely resided in the intertidal zone.

Dunkleosteus skull was noted for its hard bone and unique jaw formation
Dunkleosteus skull was noted for its hard bone and unique jaw formation

Throughout America, Poland, Belgium, and Morocco, countless fossils belonging to different species have been discovered, but due to the inconsistency of locations, it is generally accepted that they had worldwide distribution.


Based on certain current shark species, Dunkleosteus and the majority of other placoderms may have been some of the earliest vertebrates to integrate internal egg reproduction. Additionally, there have been several other placoderms discovered with what seems to be an umbilical cord mechanism, as well as additional indicators suggesting they might have been viviparous. All in all, the evidence to give a definitive answer is still lacking due to the fossilization variability of soft anatomy parts, including sexual organs. 


Dunkleosteus is regarded as one of the earliest real apex predators on the planet and served as the top predator in its original environment. They were, therefore, unlikely to be attacked by or even be the prey of other creatures. However, recent findings revealed scratches and piercing traces on a fossilized Dunkleosteus exoskeleton formed from a larger Dunkleosteus. 

Despite being an apex predator of its time, Dunkleosteus is thought to have engaged in cannibalism
Despite being an apex predator of its time, Dunkleosteus is thought to have engaged in cannibalism

According to this data, they engaged in cannibalism, with larger animals preying on smaller ones. This may explain why smaller Dunkleosteus inhabited shallower ocean areas, distant from its deeper regions, while larger ones reigned supreme.

Facts about the Dunkleosteus

  1. Dunkleosteus would cannibalize 
  2. smaller members of its own species.
  3. The largest Dunkleosteus was 33 ft long and weighed around 9,000 lbs.
  4. Dunkleosteus had no real predators. 
  5. Dunkleosteus includes ten species that range in size and habitats but are connected by their signature skull.


Why did Dunkleosteus become extinct?

During the climax of the Devonian Era, a catastrophic extinction catastrophe caused them to become extinct. Due to the significant drop in oxygen levels brought on by this catastrophe, smaller marine species fared better in terms of survival than large species such as the Dunkleosteus. 

How fast could a Dunkleosteus swim?

Dunkleosteus is thought to have had poor swimming skills. Given their accessibility and the fact that Dunkleosteus was primarily found in shallower environments, their rigid build allowed them to protect themselves against many species and prevented Dunkleosteus from going deep underwater in pursuit of food.

Was the Dunkleosteus larger than Megalodons?

Although both were top predators in their time, Megalodons were twice the size and weight of the largest Dunkleosteus. In a hypothetical fight, Megalodon’s teeth would have a chance at piercing the hardened exoskeleton of the Dunkleosteus by swallowing their heads whole and splitting them in half.

How strong was the Dunkleosteus bite?

Dunkleosteus lacked teeth, as with all Placoderms. Its hardened jaw plates, meanwhile, created enormous, self-sharpening blade-like protrusions. Dunkleosteus has a chomping force of 1,000–21,000 pounds per square inch, and It could eat through bone like a cracker. A really huge crocodile could represent a contemporary example.

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