As one of the most bizarre prehistoric sharks, Hybodus had strange horns on the top of their heads. When they bit into large prey, they twisted to get a chunk of flesh. These predators had acute hearing, and the sound of splashing betrayed an animal in distress.
Hybodus sharks appeared at the end of the Permian and disappeared at the mid-Cretaceous. They are prey of larger predators including Liopleurodon, (as featured in Walking with Dinosaurs) which may explain why its dorsal fin evolved a spike - to make swallowing them harder. They also probably lived in the shallows, away from giant marine reptiles, including pliosaurs.
Appearances in the programmes
Several Hybodus were seen watching a mother Ophthalmosaurus struggle to give birth. As the sharks homed in, they scattered as the massive silhouette of an old, bull Liopleurodon appeared. Another Hybodus was seen pursuing an Ophthalmosaurus pup. The pup hid inbetween some coral and then darted away. Then the Hybodus shark gave up.
Months later, several Hybodus were seen following a trail of blood left by a female Liopleurodon whose flipper was ripped by the old bull Liopleurodon.
- Hybodus was the first shark to appear in the Walking with... series.
- In Cruel Seas, Hybodus was identified as a shark. The directors likely thought describing the species of shark in the episode was unnecessary, so they left it out. However, Hybodus would later be identified as its genus name in Sea Monsters.
- The model of the Hybodus would be reused for the sharks in WWB episode Whale Killer. It would also be remodeled for Stethacanthus in Sea Monsters and Walking with Monsters.