Prehistoric waters held all kinds of fascinating creatures, including ancient sharks. These sharks typically lived for millions of years, but changes in habitat, lack of prey, and other evolutionary factors made it impossible for them to stick around until today.
We mostly discover these extinct sharks through their teeth, which they grew in large numbers throughout their lives and which hold up better to time than the cartilage throughout the rest of their bodies.
Sharks as a species are still going strong, though, and they remain one of the oldest creatures on earth!
Unfortunately, overfishing has endangered over one third of today’s sharks—so the fight isn’t over yet. We need to help to reduce overfishing and climate change before it’s too late, so that many more sharks aren’t added to this list of 11 types of sharks that went extinct.
Read on for the top facts about the most interesting extinct sharks.
Megalodon is the largest shark that ever existed. It measured 49-59 feet (15-18 meters) in length, which scientists have judged by the size of its massive teeth.
Megalodon translates directly translates to “large tooth,” and these teeth have helped researchers learn a lot about the animal, from its size to what it ate. An entire Megalodon skeleton has never been found preserved.
The species survived for over 16 million years and went extinct around 2.6 million years ago. They thrived around the world during their prime, and their teeth have been found on nearly every continent! (Antarctica being the exception.)
We don’t know for sure what killed off the Megalodon all those years ago, but it was likely the cooling of the planet. These sharks lived in warm waters, and the ocean cooling would have led to a reduction in its habitat and prey.
The next shark on our list is much smaller. Cladoselache sharks measured only 4 feet (1.2 meters)! Their bodies were different to other sharks of the time, but were perhaps perfectly adapted to speed through waters after prey.
They had very few scales and no claspers (organs which are used to transfer sperm from male to female sharks). It’s not known for certain how they reproduced, but they lived in the waters of North America and Europe for over 100 million years.
Their extinction occurred around 250 million years ago.
Another small shark, the Stethacanthus grew to just 3 feet (1 meter) long. Its name, which translates to “chest spike,” came from the flat protrusion on the backs of the male sharks.
It’s thought that they used it to attach themselves to female sharks when mating. It also slowed their movements considerably. The Stethacanthus were likely bottom-feeders rather than speedy predators.
They lived in North America, Asia, and Europe. The species died almost 300 million years ago.
The Orthacanthus was a freshwater shark native to Europe and North America. Its defining feature was the spike that jutted from its head, which is thought to have deterred predators and may have even been poisonous!
It lurked in waters dense with foliage, which provided great hunting grounds for stealth predators.
Orthancanthus sharks navigated these waters with long, lithe bodies made to fit through tight crevices. For this reason, they are sometimes referred to as the “eel shark.”
They went extinct around 260 million years ago.
The Xenacanthus is basically a mini eel shark. At around 3 feet (one meter) long, it was only one third of the size of Orthancanthus.
The two sharks lived alongside one another, with Xenacanthus likely feasting in hard-to-reach areas between plants or land. They did not compete with one another, but instead ate prey of different sizes.
Living a little longer than its counterpart, Xenacanthus went extinct a little over 200 million years ago.
These sharks were small and quick, built to chase down prey at top speeds. They had small horns at the top of their heads and compact bodies measuring 6-8 feet (2-2.5 meters) in length.
They lived in shallow waters and ate their prey in bites, twisting their heads to rip their food to pieces.
Hybodus went extinct 65 million years ago. The most common Hybodus fossils are teeth and spines.
Ptychodus lived until around 85 million years ago. This carnivore ate mostly shellfish and mollusks, with teeth specialized to break through hard shells.
Though it’s mostly small sharks who eat this diet today, Ptychodus sharks fed on the much larger ancestors of these animals.
These include the 9-foot (2.7 meter) mollusk, Platyceramus, and the 6.5-foot (two meter) clam, Inoceramus.
At around 33 feet (10 meters) long, Ptychodus sharks were one of the largest known sharks in the ocean at the time. Genetically, they were very closely linked to the sharks of today!
These sharks lived all around the world until about 80 million years ago. They competed with pliosaurs and mosasaurs for food, as they all ate large prey.
One of these prey, a 20-foot long fish called Xiphactinus, was found undigested inside of a fossilized Cretoxyrhina.
Cretoxyrhina wasn’t at the top of the food chain, however, as it was hunted by larger sea creatures like the reptile Tylosaurus.
Larger than a great white at up to 26 feet (8 meters) in length, these sharks were also incredibly quick—they might have moved as fast as 43 miles (70km) per hour! If they were still alive today, they would be the fastest shark in the world.
Otherwise known as the scissor-tooth shark, Edestus sharks lived over 300 million years ago.
Their teeth grew differently to modern sharks, forming a single line from the back of their mouths to the front. As new teeth grew in at the back of their mouths, this caused the newer teeth to press forward to the outside.
Lack of fossils from the sharks’ bodies leave a lot of questions unanswered. They likely hunted by either slicing through or stabbing their prey with their unique teeth, but what they ate in particular is unknown.
One theory is that the sharks were specialized hunters. If this were the case, the death of their prey may have led to their own extinction.
The Scapanorhynchus went extinct just over 5 million years ago. Before then, they swam the Atlantic ocean for over 140 million years.
They had long, pointed snouts and teeth designed to catch and tear apart prey, but most of the sharks in this genus were incredibly small! Most species measured around just over 2 feet (65 cm).
Scapanorhynchus sharks hunted by lurking in the ocean’s depths, waiting patiently for prey to pass by. They weren’t fast swimmers and thus, were quite passive hunters!
These sharks are very similar to the goblin sharks that live today, but some key changes differentiate the two including their fins.
Anisopleurodontis is a genus of shark, but this genus contains just one species! They went extinct almost 300 million years ago and were closely linked to ratfish.
They’re thought to have been around 6-10 feet (2-3 meters) long, with large heads and mouths. Unlike modern ratfish, the Anisopleurodontis may have only eaten fish. It’s also possible that their diet was a mix of fish and shelled prey.