Prehistoric Ocean Creatures that Still Exist Today

Prehistoric ocean creatures that still exist today

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Our oceans are filled with over 228,000 known creatures, and it’s thought that there are still up to 2 million we don’t even know about yet. Among these creatures are some that have dwelled in our waters for longer than humanity itself.

Surviving Prehistoric Ocean Creatures

From ancient species of sharks to crustaceans and all the weird and wonderful creatures in between, our oceans are bursting with prehistoric life. Let’s meet some of these fascinating animals that have evolved for millions of years and still frequent our oceans.

1. Coelacanths

Coelacanths have managed to survive for millions of years

Fossilized remains of coelacanths have been discovered that are thought to be up to 410 million years old, making these fish older than the dinosaurs! While there may once have been up to 90 species, there are now only two that remain. These are the Indonesian coelacanth and the West Indian Ocean coelacanth.

These lobe-finned fish typically grow to around 5 feet (152 cm) in length, and rather than being relatives of ray-finned fish, they’re more closely related to tetrapods. Amazingly, these creatures were once thought to be extinct until they were rediscovered off the coast of South Africa in the late 1930s. 

Sadly, while the coelacanth has managed to survive for millions of years, these fish are now under threat. In South Africa, it’s believed that there are as few as 30 individuals left in the wild, and this population is likely to dwindle as a result of oil wells.

2. Frilled Shark

The frilled shark (Chlamydoselachus anguineus) may live at depths of up to 3300 feet, it was discovered some time ago back in 1879.

The name frilled shark makes this sound like a pretty and ornate creature, but this is quite misleading! The frilled shark is actually one of the most terrifying prehistoric marine animals I have ever seen and it can grow up to 7 feet in length (213 cm).

Aptly named the living fossil, these sharks are thought to have inhabited Earth’s oceans for more than 80 million years. They’re so ancient that any relatives are long extinct and the frilled shark is a pretty rare sight itself. In fact, they’re listed as near threatened on the IUCN Red List, although no conservation efforts are currently in place.

That said, where sightings have occurred, they’re almost global, but the frilled shark spends most of its time in open water and is rarely found close to the shore. With rows of needle-like teeth and a rather shocking-looking head, the frilled shark has startled fishermen that have stumbled upon it. 

Since they’re not spotted all that often, frilled sharks remain something of a mystery to scientists. However, we do know that they swallow their prey whole and usually feed on squid and deep-sea fish.

3. Horseshoe Crabs

Horseshoe crabs are also called living fossils since they have not changed much at all in the last 200 million years

Predating the dinosaurs, it’s thought that the horseshoe crab has been around for more than 445 million years. However, they’re actually a relative of the arachnids and not crabs, as one might first imagine.

These are also called living fossils since they have not changed much at all in the last 200 million years. Today, there are four species of horseshoe crab that can be found in the ocean and they live off the Atlantic coast of North America from Nova Scotia down to Mexico.

Today, most horseshoe crab species grow to around 24 inches (61 cm) including the tail. However, their ancient relative, the merostomata is thought to have grown to more than 9.8 feet (3 meters)!

They spend most of their time in deeper waters but will return to the shore during the breeding season. With four sets of legs, it’s easy to see how these crabs are closely related to spiders. They also have an additional set of legs attached to the mouth which they use to crush and move food to their mouths which may include things like worms and crustaceans.

Oh, and did you know that their blood is blue?

4. Nautilus

Nautilus are marine mollusks that are thought to have been around for more than 500 million years

I don’t know about you, but when I’m asked to think of a prehistoric sea creature, the nautilus is one of the first that springs to mind. These are marine mollusks that are thought to have been around for more than 500 million years. What’s amazing is that, during that time, they’ve hardly changed at all. That said, it is believed that some were straight-shelled millions of years ago compared to the coiled shell we see today.

The nautilus is a slow-growing creature that takes its time moving through its environment, and it can live to be more than 100 years old! These creatures inhabit the deeper parts of the ocean and, unlike many animals that come to shore to spawn, the nautilus lays its eggs hundreds of feet below the surface. What’s more, when the young hatch, they’re not in any sort of larval stage but are fully formed, miniature versions of their parents. These traits are thought to have contributed to their ability to survive so well.

The nautilus does not have very good eyesight and is an opportunistic hunter that preys on things like crustaceans, but they are also known to feed on carrion.

5. Lampreys

The lamprey is thought to date back as many as 360 million years

Considered to be a living fossil that hasn’t changed much, the lamprey is thought to date back as many as 360 million years. According to the discovery of this 360 million-year-old fossil, scientists believe that even the behavior of these parasitic fish has not evolved over the years. 

Lampreys are pretty scary-looking creatures, it’s that mouth! While these eel-like fish might look harmless at first, once they open their toothed, funnel-like mouths, you might be forgiven for thinking that they were something from an alien horror movie!

However, it’s this mouth that allows the lamprey to attach to its host. When attached to its chosen fish, the lamprey also uses its anticoagulant saliva to stop the host’s blood from clotting as it feeds.

The lamprey is a widespread fish that is found in most temperate regions in both marine and freshwater. However, it did become extinct in some areas such as England from around the 1800s. But in recent years, the lamprey populations in these areas are on the rise again and this is thought to be down to lower pollution levels. 

6. Greenland Shark

The Greenland shark is one of the most ancient creatures in our oceans having been around for an estimated 450 million years

The Greenland shark is fascinating for a couple of reasons. For starters, it’s one of the most ancient creatures in our oceans having been around for an estimated 450 million years. But if that wasn’t enough, individual Greenland sharks have been recorded to live for a whopping 400 years making them the longest-lived vertebrates on the planet!

Greenland sharks, as you might guess from their name, are usually found in northern waters, including the north Atlantic and Arctic Oceans. However, recently scientists discovered an individual swimming around the coastline of Belize in the Caribbean Sea. While there have been reports of Greenland sharks being found as far south as the coast of Georgia, USA, they normally swim much deeper in these areas where the temperature is colder. 

Just looking at these sharks tells you everything you need to know since they have a very ancient appearance. What’s more, they’re incredibly slow growing, only gaining less than an inch every year but eventually get to more than 20 feet (6 meters) in length. This is one of the reasons they’re thought to live for so long.

7. Goblin Shark

Goblin sharks (Mitsukurina owstoni) typically live at depths of around 3000 feet, but they’re known to dive even deeper as they get older.
Dianne J. Bray – Museum Victoria / Wikimedia Commons / CC BY 3.0

Another type of shark that has called our planet home for millions of years is the goblin shark. It’s thought to have been around for 125 million years, and while it might have a strange appearance, it’s of no threat to humans at all.

Goblin sharks are pink-skinned with long snouts and, unsurprisingly, a face that looks just like a goblin (think of the David Bowie movie, Labyrinth, and you’ll be spot on.) While that toothy mouth might look threatening, it’s of great use to the shark when hunting and it can quickly extend its jaw faster than any other shark in order to catch things like mollusks and crustaceans.

Goblin sharks are mainly found in the Atlantic, Pacific, and Indian Oceans, particularly around the southeastern coasts of Australia. However, they are deep sea creatures that are rarely encountered by humans.

8. Shortfin Mako Shark

Having lived on Earth for more than 450 million years, the shortfin mako shark is one of the ocean’s oldest inhabitants

Having lived on Earth for more than 450 million years, the shortfin mako shark is one of the ocean’s oldest inhabitants. From the mackerel shark family, there are now two living species of shortfin mako shark which are found in all tropical and temperate waters.

These sharks live in the open ocean and are aggressive predatory fish that could pose a danger to humans. It’s thought that the modern great white shark is a descendant of an ancient type of mako shark. 

Sadly the shortfin mako shark is now listed as endangered by the IUCN Red List. These sharks can grow up to 13 foot (4 meters) in length and can weigh well over 1200 lbs (544 kg)! However, unlike species such as the Greenland shark, these sharks are much shorter-lived and don’t tend to live past the age of 30.

9. Ghost Shark

Ghost sharks are deep-sea animals that are thought to be more than 280 million years old
NOAA / Wikimedia Commons / Public Domain

The ghost shark has long been a mystery to scientists as its features don’t allow them to classify it with other animals. Things like winged fins and oversized eyes make this a creature all of its own. At least, that’s what we thought until a giant skull was discovered, thought to be more than 280 million years old.

That has allowed scientists to figure out the ancestry of the ghost shark which is now believed to be a relative of the chimera; an ancient type of fish. Unlike bones which form the structure of regular fish, the chimera had cartilage plates which is a feature also seen in the ghost shark. Although it’s not actually a type of shark at all!

Ghost sharks are deep-sea animals that are found in the Pacific Ocean, largely around the coasts of Australia and New Zealand. They’re not often encountered by humans as they spend most of their time up to 6,560 feet (2000 meters) below the surface where they hunt for shellfish and mollusks.

10. Whale Shark

The whale shark is a tropical inhabitant that is thought to have been around for more than 60 million years

The name whale shark might be pretty confusing, but this is a species of shark, not whale. These are the biggest type of fish in our oceans that we’re aware of and are filter feeders with a friendly, gentle disposition. So much so that it’s not uncommon for them to interact with humans.

An endangered shark species, the whale shark is a tropical inhabitant that is thought to have been around for more than 60 million years.

Whale sharks can grow up to 33 feet (10 meters) and weigh as much as 41,000 lbs (18,597 kg)! In order to get enough food to sustain their gigantic bodies, these large fish must travel up to 5,000 miles (8,046 km) every year and are known for their migratory behavior.

11. Pygmy Right Whale

An ear bone from a pygmy right whale was discovered more than 60 years ago but it’s finally been dated and is thought to be around 6 million years old / Wikimedia Commons / CC BY 3.0

A type of baleen whale, the pygmy right whale was thought to have been extinct until 2012 when it was rediscovered. It’s the smallest type of baleen whale and typically doesn’t grow much bigger than 21 feet (6.5 meters).

These whales are a mysterious species that hasn’t been studied all that much. They are found in the southern hemisphere, mainly in temperate waters around Australia, Chile, South Africa and several other locations.

These whales are very difficult to spot owing to the fact that they spend very little time at the surface of the water. An ear bone from a pygmy right whale was discovered more than 60 years ago but it’s finally been dated and is thought to be around 6 million years old.

What’s interesting is that, while these whales are now largely confined to the southern hemisphere, fossils have been found in Japan and Italy, indicating that their populations may have once been much more widespread.

12. Jellyfish

Jellyfish have been in our oceans for more than 500 million years

Jellyfish are extremely primitive creatures, and there are as many as 2000 known species, although it’s thought there could be hundreds of thousands. It’s thought that these amazing creatures have been in our oceans for more than 500 million years, and recently scientists have been looking at the jellyfish genome to discover how they alter their form, which in turn gives us a clue as to how they have evolved and survived with an incredibly complex life system. 

Jellyfish are found in waters all over the world depending on the species. There are even some jellyfish that are able to survive under sea ice thanks to the cold conditions slowing down their metabolism and even causing them to live for several years as opposed to just months. 

Their ability to survive for so many millions of years may also be down to some species’ ability to never die. That’s right, the immortal jellyfish will revert back to an earlier life stage essentially meaning that it can never die. That is if it isn’t caught by a predator. 

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