The three-foot long Xenacanthus shark existed 345 million years ago during the Devonian Period, and it lived until the Permian Period.
These particular sharks were freshwater inhabitants that typically dwelled in rivers and lakes.
The Xenacanthus owned V-shaped teeth that enabled them to eat bony fish and crustaceans.
Although the Xenacanthus was most definitely a type of shark, its appearance closely resembled that of an eel.
Xenacanthus sharks had an elongated, thick spine that extended throughout their bodies, starting from the back of their skull.
It is believed that the spine of a Xenacanthus was used as protection against possible predators.
Following this eye-catching spine was a dorsal fin that looked like a ribbon.
The spine and dorsal fin of the Xenacanthus is the reasoning behind the shark’s eel-like appearance.