10 Oldest Animals That Ever Lived

Most of Earth's history is uncovered through in-depth research into fossils. Scientists have been able to dig into the present and past creatures, only to find that some species have lived for millions of years yet remain unshaken. The animal kingdom remains lively, thanks to these oldest living creatures. 

Martialis Heureka Ant - 120 million years old 

The Martialis Heureka Ant is a terrestrial creature and one of the oldest animal species on our planet. Unfortunately, they're elusive and not known to humans. Even though they've been around all this while, scientists only discovered them in 2008. The last of their kind to be seen was in 1923, this led researchers to believe they were no longer with us. Martialis didn't just represent a new ant species, but a whole new genus and sub-family that existed as far back as 120 million years ago. This ant species is nicknamed ant from Mars due to its weird characteristics like blindness. It's so unique that scientists placed it in its own sub family. Their discovery shows us that, there's a wealth of species with great evolutionary importance. Little is known about Martialis's biology, and behavior analysis has since been done on the ant to reveal new truths. Hopefully more details will be unearthed.

Frilled Shark - 150 million years old

Frilled Sharks are the oldest shark species on Earth, despite living for over 150 million years. These shark species are less evolved than most modern animals, their bodies are a combination of shark and eel. These sea creatures live at the bottom of the ocean and despite being caught by accident, they're rarely encountered by humans, leading everyone to believe there are no more. This deep sea dweller lives between 390 and 4200 ft below the surface of the water. Although this animal swims in the deep seas, it's named after its gills. Their first pair of gills stretch across their throat but other sharks have separate gills in total. They boast six pairs of gills with frilly edges, an open mouth reveals more than 300 teeth neatly lined in 25 rows. It's unlikely you'll encounter them, but it's safe to stay far away from them if you do.

Sturgeon - 200 million years ago

Sturgeon is an umbrella term for all the species that existed 200 million years ago. Despite being ancient, they're critically endangered due to theactivities of human predators. This animal is harvested for its row which is used in making caviar. Caviar consists of egg strips from mature females, they grow and mature slowly. Hunting pollution and habitat encroachment threaten their existence. The good news is that they can produce millions of eggs within a short period of time. Unfortunately, only a few of the eggs survive as humans feast on them without remorse. The International Union for Conservation of Nature and Natural Resources says, more than half of them are critically endangered, with the Chinese variant being most endangered. Sturgeons have bony plates that cover their head and five rows of similar plates on their body, their toothless mouth is preceded by four sensitive tactile barns which they drag over the bottom in search of smaller fish. They're found in rivers around Ukraine, Russia, and parts of North America. Young ones proliferate mental maturity, after which growth is slowed for several years. 

Tadpole Shrimp - 220 million years old

Even though they've been around for over 220 million years tadpole shrimps are classified as endangered species. Would this scare cause these animals to disappear anytime soon? Certainly not. In 2010, scientists discovered why this animal continues to survive through terrible living conditions. After this revelation, scientists are convinced that there could be more of them in the wild, and their extinction wouldn't happen anytime soon. These amazing animals have an interesting life cycle. When their temporary ponds are dry, their eggs are dormant and wait patiently for the rain and the pond is full. They burst open and grow exponentially before the pond becomes dry again, these eggs adapt to terrible living conditions and would last for many decades without dying. This means that, even if the ponds dry off, all was not lost and the cycle continues whenever the pond is full. Native tadpole shrimp are found in the New Forest in Southern England and near the Solway Firth in England.

 Lamprey - 360 million years old

Lampreys are ill-like parasites with circular mouth-holes filled with dozens of small sharp teeth used to feed on their fish host, and suck their blood. Quite scary, isn't it? Well, you're hoping that they'll disappear and never return, you'll have to go way back to the paleozoic era and scientists saw some fossils of 360 million year old lampreys. They launched a discovery to see if they had similarities with present-day creatures, lo and behold they were essentially the same as those living today. Therefore Lamprey qualifies as one of the oldest creeps on the planet. What's even more exciting about these animals, is the high regard in which scientists hold them. Ecologists have affirmed that they're instrumental in maintaining the health of rivers. Medical researchers say the animal can heal itself after severe nerve damage. To add to these discoveries, evolution biologists say they were among the first backboned animals to evolve. Therefore, they carry essential information about their origins. Lampreys lack jaws, their mouth is a permanently open ring filled with weird looking teeth.

Jellyfish - 505 million years old 

As we count down to the world's oldest animals, we encounter those that are incredibly primitive. Jellyfish lived in a time when land animals didn't exist, they lived as far back as 505 million years ago. It means that they're twice as old as we thought. In 2007, scientists from the University of Kansas found new fossil evidence, dating back a half a billion years. This is almost 200 million more than the oldest known fossil. It's therefore accurate to say that jellyfish are unapologetically one of the oldest animals to roam the surface of the Earth. One gesture that kept this animal alive against all odds is the fact that it's immortal. It transforms from an adult species back to a baby whenever it's threatened. It doesn't stop there, it does this over and over again especially during emergencies. Scientists had wondered how they managed to survive for millions of years until they learned of this skill sometime around the 1990s.

Coelacanth - 360 million years old

They all thought the Coelacanth was extinct until we realized they weren't. they just didn't want to be known and achieved their game plan. Millions of years passed and nothing was heard about them until 1938. When science dug deeper, they found a similar fish and investigated its properties only to realize they were identical to the ancient fish. However, they evolved to the point that they crawled out of the water and became the first land vertebra. In fact, researchers have even reported the genome sequence of the coelacanth for the first time. Understanding their blueprint helps us know how and why they evolved into what they are today. Coelacanth were thought of the ancestors of gentropods, but recent analysis revealed that lungfish are more closely related to tetrapods. They retain their oil-filled notochord that serves as a backbone in many other vertebrates this notochord is replaced by the vertebral column. As the embryo develops, this creature's brain occupies only 1.5 percent of their cranial cavity while the rest of the brain case is filled with fat.

Horseshoe Crab - 445 million years old

Horseshoe crabs are one of the most well-known living fossils, having lived unchanged for over 445 million years. In 2008, a group of Canadian scientists found a new horseshoe crab fossil. Although this animal was listed among one of the oldest on Earth, the new fossil was over 100 million years older than the previous ones. What's even more exciting is that they have striking similarities with all the previous ones that were seen. The name horseshoe crab originates from the shape of their head since it resembles the shoe of a horse's foot. The head is the most significant part of the body as it boasts much of the biological and nervous organs. The head houses the brain, glands and nervous system. The head also serves as protection for their extensive set of eyes, these unique crabs have nine eyes scattered around their body and several light receptors near the tail. Two most oversized eyes help find their mates, while others are light receptors used to determine movement and changes in the moonlight.

Nautilus - 500 million years old

Nautilus have lived for half a billion years, there's been no reset or reboot for them as they've managed to scale through all the mass extinctions threatening our planet. You can also describe them as one of the fiercest in the animal kingdom, owing to their resistance to extinction despite many years of survival. They now risk going extinct because humans like cool shells, they harvest their shells due to their unique spiral shells and use them for decoration. Aside from that, they've been overfished in recent years to the extent that only a handful of them are left. Before now, you could catch hundreds of them in a day but today you'll barely find five after a whole day's search. Nautiluses are distant cousins of cuttlefish and squid, their timelessness has earned them a title. Living fossils recent sightings indicate there's more about this creature than meets the eye.

Sponge - 800 million years old

It's unclear how long sponges have lived but scientists are confident that they've existed for over 760 million years. Aside from bacteria and microorganisms, they're classified as one of the oldest living creatures on Earth. The oldest evidence of the sea sponge was a fossil dating back to 760 million years ago, it hid between an ancient rock until it was eventually unearthed. This animal beat the previous record for the oldest sea sponge 635 million years old. We are convinced that older fossils are yet to be found, but scientists have ruled out the possibility. Claims of ancient fossilized life like this one illicit controversy, this is because ancient creatures could be similar to those beef today but may be a little different and a bid to describe this creature.