In 1938, a South African fishing boat reeled in an amazing catch — a coelacanth, a fish thought to have been extinct for 65 million years. While the coelacanth may be the best-known example of a “living fossil,” it’s not alone. An animal is considered a living fossil if it has few remaining relatives and is representative of a genus or species that we otherwise only see in modern fossil records. Such animals are often so well suited to a stable environment that they have had little need to evolve, sometimes over geological spans of time. Many of these species have survived several successive mass extinctions, and have been with us virtually unchanged for hundreds of millions of years. And while crocodiles and alligators are commonly cited as prime examples of living fossils, there are some far stranger examples in the animal kingdom.
A variety of giant salamander, the lineage for the hellbender dates back to the middle of the Jurassic period some 170 million years ago. The modern hellbender exists in a range of the eastern United States from the Ozarks to southern New York. They are also sometimes referred to as “mud-devils” or the “Allegheny alligator.” Hellbenders occupy a unique ecological niche both as predator and prey and can grow up to 29 inches in length, making them the largest salamander species in North America.
9. Purple Frog
In 2003, researchers announced the discovery of the purple or pig-nosed frog. This bizarre-looking amphibian exists in a narrow range of habitat in southern India. The closest known living relatives to the purple frog exist in the distant Seychelles, which lends credence to the theory that the Indian landmass was once joined to regions to the south before wedging under the Himalayas. The purple frog spends most of its life underground and only surfaces for a few weeks during the monsoon season to breed and mate.
8. Vampire Squid
The vampire squid’s scientific name alone is enough to land it on this list. Its scientific name, vampyroteuthis infernalis, literally translates to the “vampire squid of hell.” A distant cephalopod relative to modern squid and octopi, the vampire squid actually feeds on detritus that litters the ocean. The very fact that vampire squids occupy an ecological niche as the ocean’s “garbage cleanup squad” has meant very little competition for them, and has given them little need to evolve.
Having changed little in the last half billion years, the chambered nautilus comes to us straight from the Paleozoic era several hundred million years ago. This cephalopod lives in the tropical western Pacific Ocean, and subsists by vertical migration, rising to hunt for prey at night before sinking back into the dark depths of the sea by day. The nautilus is prized for its white- and orange-striped shell, which is up to 10 inches in diameter.
A close relative to the guinea pig, the capybara is a large rodent that ranges throughout the Amazon jungle and central South America. While “large” is a relative term, consider that a capybara can grow to more than 4 feet in length. Some of the oldest capybara fossils are found in 9 million-year-old rocks in Argentina dating from the Late Miocene epoch. These creatures have become trendy pets in some circles, despite the fact the capybara has special needs — such as constant social interaction — that are difficult for many owners to meet.
5. Monotremes (Platypus and Echidna)
The only egg-laying mammals, platypuses and echidnas are an extremely valuable link to early mammalian evolution, with a lineage dating back more than 150 million years. In fact, scientists several years ago decoded the platypus genome and confirmed these were the earliest known offshoots of the mammalian family tree. Although sometimes referred to as the spiny anteater, the echidna resides in New Guinea and Australia and is not a relative to the anteaters prevalent in the Americas. As for the platypus, which is also native to Australia, the male platypus has a toxin-releasing spur on its hind foot, making it one of the very few venomous mammals in the world.
At first glance, the okapi looks like a cross between a zebra and a small deer. In fact, the closest living relative to the okapi is the giraffe, and the two are the only remaining examples of the family known as Giraffidae. Found only in the central African nation of the Democratic Republic of the Congo, a 2013 study found that only an estimated 10,000 okapi remain in the wild. In 2013, the Lowry Park Zoo in Tampa Florida celebrated the rare birth of an okapi in captivity.
3. Goblin Shark
A weird name, and an even weirder appearance. A rare species of shark that lives in the deep oceans worldwide, the goblin shark is the only remaining example of its family and genus. Their ungainly appearance is characterized by a long, flat snout and protruding jaws. And while other sharks have been the focus of intensive study, goblin sharks remain a mystery to scientists.
2. Mantis Shrimp
Not really a shrimp nor a mantis, a mantis shrimp can grow up to 18 inches in length. Mantis shrimps have powerful claws, and there are anecdotal stories that these have been known to actually break through aquarium glass. The mantis shrimp has some of the most specialized and extraordinary vision in the animal kingdom, consisting of eyes mounted on independently moveable stalks that can sense both multispectral and polarized light. This unique design has even inspired researchers to attempt to build a tiny camera that could be used to detect cancer.
One of nature’s greatest survivors is also one of the tiniest. Tardigrades are found worldwide, and are typically less than a millimeter in size. These microscopic “water bears” are very rugged and have existed for hundreds of millions of years virtually unchanged. Tardigrades are typically found by the thousands in moss, can survive in extreme environments and can withstand high doses of radiation. It was for this reason that tardigrades were selected for a round-trip mission to the moons of Mars on the ill-fated Russian Phobos-Grunt spacecraft that crashed back to Earth in early 2012.