The animals we see around us are only 10 percent of all species that have ever lived on earth. Of these animals, some have survived the various shifts of earth's geology through evolutionary adaptation and managed to survive extinction for millions of years. Here is a look at some such prehistoric animals that have stood the test of time and are still around today.
Found in Siberia and parts of North America, Sandhill cranes are believed to have been in existence for 10 million years, as can be understood from their structural similarity with a fossil dating back to the Miocene epoch (some 10 million years ago).
This shark species has hardly changed in appearance in the 80 million years of its existence, earning it the epithet of "living fossils." A deep-sea creature, this rarely spotted shark has 300 needle-shaped teeth.
Chinese giant salamander
The largest amphibian in the world, the roughly six-foot-long (1.8 meters) Chinese giant salamander is currently listed as critically endangered by the International Union for the Conservation of Nature (IUCN). Fossil records indicate that the animal has undergone little change in 170 million.
This elusive, herbivorous mammal is related to horses and rhinoceros. The earliest fossil evidence of tapir dates back to the Early Oligocene period (over 20 million years ago) and they have not changed much since. Of the five species, four are found in Central and South America and one in Asia. Four of them are listed either as endangered or vulnerable.
Horseshoe crabs have nine eyes and their hard exoskeleton hides 10 legs. Named so because of their shape, the animal is not actually a crab, but a close relative of spiders and scorpions. They have been swimming in the earth’s waters for over 300 million years and predate dinosaurs.
The members of this order of reptiles – crocodiles, alligators, caimans and gharials, among others – evolved around 85 million years ago when dinosaurs were dying out. What makes crocodylians truly prehistoric is not just their appearance but also the fact that the order is itself an offshoot of the Crocodylomorpha – a group that evolved over 205 million years ago.
This shrimp has been in existence for at least 220 million years ago, which means it was around when dinosaurs roamed the planet – making it one of the oldest living creatures. The survival of tadpole shrimps is made possible through an evolutionary process called diapause, in which the eggs can remain in a dormant state for up to 27 years till the environment is conducive for them to hatch.
Found only in New Zealand, the tuatara is one of the oldest living reptiles on earth. They look like lizards but are completely distinct. They are the only surviving members of the order Sphenodontia, which was well represented during the age of dinosaurs. The lifespan of a tuatara can extend up to 100 years in the wild.
Considered to be a “living fossil,” the marine creature found in Indian and Pacific oceans has been thriving for at least 500 million years. They are the only cephalopods with a shell, which has chambers that help them remain afloat and catch prey.
A fossil of an echidna dating back 17 million years ago to the Miocene epoch reveals that this small anteater, endemic to Australia, Tasmania and New Guinea, has hardly undergone evolutionary change. The echidna – both short and long beaked – is one of the only two mammals (the other being platypus) that lays eggs.
It is difficult to find jellyfish fossils since their bodies are 95 percent water, but research reveals that they have been in existence for at least 700 million years. Jellyfish are common and can be found in seas and oceans around the world.
Research reveals that precursors of the modern turtles lived around 220 million years ago in the Triassic epoch. However, the exact group of reptiles from which they descended is yet to be determined. Both land and sea turtles can be found around the world, but some are listed as endangered species.
The venomous mammal native to the Caribbean region branched from a family of other mammals some 76 million years ago in the Cretaceous period – the last age of the dinosaurs. Only two species of this small, burrowing, nocturnal shrew exist – the Hispaniolan and the Cuban (pictured), both listed as endangered by IUCN.
Endemic to Indonesia, the Komodo dragon is the world’s largest and heaviest lizard, growing nearly 10 feet (three meters) long and weighing around 150 pounds (70 kilograms). Though Indonesia was widely regarded as their birthplace, the discovery of fossilized bones in Queensland in 2009 has led scientists to believe that Komodo dragons originated in Australia roughly four million years ago and then dispersed westward.
The sturgeon looks like a primitive fish and has been around for at least 250 million years, as fossil records show. The fish, which can grow up to a length of seven feet (two meters), is found in rivers and lakes in Europe and North America. They are currently classified as critically endangered by IUCN.