Kingdom Animalia
Phylum Chordata
Class Chondrichthyes
Subclass Elasmobranchii
Order Xenacanthida
Family Xenacanthidae
Genus Xenacanthus
1st Species Xenacanthus atriossis
2nd Species Xenacanthus compressus
3rd Species Xenacanthus decheni
4th Species Xenacanthus denticulatus
Other attributes
Time Range 360-202 mya
Location United States of America, Czech Republic, India
Name Meaning Foreign spine
Physical Dimensions 1 meter long
Dietary Classification Carnivore

Xenacanthus is a xenacanthid xenacanthid cartilaginous fish from the Late Devonian-Late Triassic of the United States of America, Czech Republic, and India. It was named in 1848 by Heinrich Ernst Beyrich. It was a unique, widespread, and successful shark, fulfilling the very latter by lasting for 3 periods.


Xenacanthus was a unique shark. It was a cartilaginous fish with a long, eel-like body, a small, pointy head with big jaws, a ribbon-like tail fin, and a long spine on its head. Its body would have been covered in scaly skin.


Xenacanthus was a predator, feeding on small fish and crustaceans. Its teeth had a unique V-shape, and were used for getting a hold of struggling prey.


Xenacanthus lived in freshwater rivers, swimming around in search of prey. It swam much like a conger eel, moving its tail from side to side to propel it through the water. The long spine on its head is speculated to have stopped predators like Dimetrodon or Eryops from effortlessly biting its head off, and some may even speculate that it was venomous (like the barb of a stingray). It would have been an ambush predator, floating a meter below the surface, right before gaining a burst of speed to snatch prey.

In popular cultureEdit

Xenacanthus was featured in a special episode of the documentary River Monsters, appearing alongside Xiphactinus, Leedsichthys, Megapiranha, Helicoprion, Dunkleosteus, and Rhizodus as candidates for the most terrifying prehistoric river dweller. During the research about it, it is compared to the alligator gar, mainly as a reminder about its teeth and hunting style.

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