With vast oceans and dense jungles and forests, there’s plenty of space on earth for all sorts of animals to stay hidden. It’s estimated that we share this planet with as many as 8.7 million species. As many as 91% of plants and animals in the water and 86% of those on land have not yet been named and given taxonomy. Most of the world’s undiscovered species are sorts of insects: As of 2010, 1.7 million species of plants and animals had been classified, and there could be as much as 4 million insects not yet classified and 500,000 arachnids undiscovered.
Most of the creatures scientists have not yet observed are very tiny, but even large species like the mountain gorilla were not documented until 1902. The giant squid was not filmed in its natural habitat until 2012. In fact, countless species go extinct before they are even discovered.
The fact that scientists don’t know exactly how many species there are means they don’t know exactly how many are becoming extinct, either. However, what is clear is that we’re losing species at an alarming rate. Experts believe as much as 0.1% of all species become extinct each year – much higher than the natural extinction rate. However, because of the vastness of the world’s ecosystems it’s not uncommon for an animal to be reported extinct only to be rediscovered years later alive and well. This phenomenon is known as a Lazarus species; a reference, of course, to the biblical figure of Lazarus who was brought back from the dead. There have been numerous examples of plants and animals officially disappearing from the realm of the existent, and in some extreme cases these species are rediscovered millions of years after they were thought to have become extinct. Below, we’ve taken a look at ten of the more intriguing cases of these Lazarus animals.
10. Cuban Solenodon
Wilhelm Peters, a German naturalist, discovered this rare rodent in 1861. Since then only 37 have ever been captured. In the early 1970s, scientists believed the animal to have gone extinct because no specimens had been caught since 1890. The last time the animal was caught in the wild and studied, however, was in 2003. These nocturnal shrew-like creatures are difficult to find because they only come out under shadow of darkness.
9. Monito Del Monte
This small marsupial is native to Chile and Argentina. Before it was found in South America, scientists believed it had become extinct 11 million years ago, because only fossil records existed. The Monito Del Monte is a relative of Australian marsupials, and scientists believe this rain forest dwelling marsupial’s ancestors traveled from Australia to South America via the Antarctic during the Cenozoic era.
8. Hula Painted Frog
This rare frog was just recently rediscovered in 2011. It was thought this frog, which is native to Israel, had gone extinct after it’s habitat, Lake Hula, was drained in the 1950s. The International Union for the Conservation of Nature (IUCN) declared the species extinct in the wild in 1996; it was the very first amphibian to receive this designation. IUCN has now labeled the species as critically endangered; its known habitat is less that 2 square kilometers. Since it’s rediscovery, at least ten more specimens have been discovered.
7. Lord Howe Stick Insect
This large insect was once very common on Lord Howe Island, which is located off the coast of Australia. Sometimes referred to as the tree lobster, the Lord Howe stick insect was declared extinct in 1930 after the loss of its habitat on Lord Howe Island. In 2001 it was rediscovered on the small islet of Ball’s Pyramid; the rediscovered population consisted of only 24 individual specimens, landing this species the title of the rarest insect in the world. Melbourne Zoo has bred over 9,000 of the insects since it was rediscovered.
6. Majorcan Midwife Toad
Like the Monito Del Monte, fossil records of this toad existed before it was discovered in its habitat. When it was rediscovered in 1979 it was revealed that it was indeed a living animal and not an extinct species. It’s rare, and its conservation status is considered vulnerable. Its wild population is estimated to be between 300 and 700 breeding pairs.
5. Mountain Pygmy Possum
This Australian pygmy possum (it’s the largest of the Australian pygmy possums) was first studied via a Pleistocene era fossil in 1896. At the time it was believed to be extinct, but in 1966 a living specimen was discovered in Victoria, Australia. At the time it was the only one of its kind known to man and the following year the Guinness Book of World Records named it the rarest animal in the world. It is still extremely rare and there are only three known populations today.
4. Chacoan Peccary
With only 3000 of these animals left, it’s no surprise that it took time to discover the South American pig-like animal. First described via fossil records in 1930, this ungulate was not found in the wild until 1971 in the Chaco region of Argentina, Paraguay and Bolivia. It was thought to be an extinct animal until it was found in its native habitat. Habitat loss is a major concern for this species as its home is being transformed into grazing area for cattle.
3. Laotian Rock Rat
This rodent is found in the Khammouan area of Laos and was first scientifically described in 2005. It was determined to be a Lazarus taxon and part of a family of rodents that was thought to have gone extinct 11 million years ago; the Laotian rat, or rat squirrel, is the only remaining link to this family. The rats were first found for sale in meat markets and in 2006 the Laotian Rock was captured and filmed for the first time.
This peculiar flightless bird native to New Zealand was thought to have gone extinct in 1898, but it was in fact rediscovered 50 years later in 1948. The bird’s rediscovery was met with great interest from New Zealanders and numerous efforts have been made to keep the bird from meeting the same fate as the Huia, a New Zealand bird that has gone extinct. By early 2013 there were said to be over 250 of the takahes in the wild.
This fish is the best example of a Lazarus taxon. The fish was believed to have gone extinct 66 million years ago at the end of the late Cretaceous period, but it was discovered as a living species off the coast of South Africa in 1938. It is considered a living fossil because this fish species has evolved very little in the past 400 million years. There are two living species of Coelacanth, which are both rare. The Indonesian Coelacanth is considered vulnerable while the West Indian Ocean Coelacanth (the one rediscovered in 1938) is considered critically endangered.