A bioluminescent cockroach, a deathly omen from Maori folklore, and a parasitic wasp named after a notorious pop singer may seem vastly different, but all these creatures are recognized by science solely through their holotype. This means that only one specimen of each species is known to exist. Such animals are not as uncommon as one might think—The Encyclopedia of Life lists 61 such species. While some of these species may be lost to time, others could still be out there. Notably, the list excludes hybrids like the Indian/African Elephant crossbreed.
(Note: The images featured here serve as examples or depict close relatives, not actual photographs of the incredibly rare animals discussed.)
10. Liverpool Pigeon

The origins of the pigeon remain unclear, as there were no records of its locality or collection details, leading to much speculation. Also known as the spotted green pigeon, it acquired its more popular name from the museum where it is displayed. The bird’s small wings suggest it once inhabited a remote island with few natural predators, while its green feathers indicate a forest-dwelling lifestyle. Tahiti, a popular spot for collectors during that era, is a potential origin. The ongoing debate centers on whether this pigeon is the mysterious titi—described by Tahitians as a green and white-spotted bird—or whether titi refers to a general term for birds of this type. Early researchers, including Rothschild, speculated a connection to the Nicobar pigeon, believed to be the last living relative of the dodo, but this theory remains contentious.
The bird’s journey to England is better documented. The 13th Earl of Derby bought it from Major Davies and added it to his vast collection at Knowsley Hall in Merseyside. This collection included notable specimens such as the holotype of the night parrot and one of the only two known examples of the New Caledonian Nightjar, alongside numerous living animals and birds. Following the Earl’s death in 1851, his collection was donated to Liverpool, forming the core of The World Museum in the city.
In 2008, the bird was displayed once again in the museum, the same year it was declared extinct by BirdLife International. Initially, two specimens of this pigeon were gathered, but one was lost before it could be studied, thus still qualifying for inclusion on this list.
9. New Ireland Stingaree

It's somewhat ironic that many of these species are known by more names than actual specimens. The New Ireland stingaree, also called the black-spotted stingaree, is only known to science from a juvenile male discovered in the Bismarck Archipelago of New Ireland, Papua New Guinea, during an expedition between 1822 and 1825. Its scientific name, Urolophus armatus, translates to “armed,” referring to the fact that this stingaree is distinctive among stingrays for having dermal denticles, tough, tooth-like scales that offer protection from predators.
The specimen was transported to a museum in Paris and described by Mueller and Henle in 1841, though its current whereabouts are unknown. Scientists have requested that any future specimens be donated to museums. Since the holotype is a juvenile, much about the species—such as its lifespan and maximum size—remains a mystery. Additionally, there is limited information on its current status, as the area where it was first found is among the least studied places on Earth, though nearby surveys have failed to uncover any additional specimens.
It remains unclear whether this fish is extinct or if its habitat has a very restricted range. If it is extinct, overfishing is unlikely to be the cause, as there is little fishing activity in its region. However, oil and gold exploration in the area could pose a potential threat to the local wildlife.
8. Mauke Starling

In 1825, naturalist Andrew Bloxam of HMS Blonde shot a kingfisher, a pigeon, and a starling during a brief visit to Mauke in the Cook Islands. Little did he know, the starling would become the focus of an enduring mystery.
The skin of this bird, now housed in The Natural History Museum in London, was labeled as 12.192 and was long informally known as the “mysterious starling.” For years, its history was unknown, and it was mistakenly believed to have been collected during Cook’s second voyage. Confusion over mislabeling and renaming compounded the mystery. In 1986, Storrs Olson, an American ornithologist from the Smithsonian, gained access to Bloxam’s original diary. Upon reviewing it, he found Bloxam’s descriptions and measurements matched the well-preserved specimen, solving the puzzle. Today, this bird is recognized as a valid, distinct species.
Ornithologists did not return to Mauke until the 1970s, and there were no additional sightings of any bird matching the description of the starling. It is now considered extinct, likely due to predation by introduced rats, which had already been a problem on the islands during Bloxam’s visit. The fate of the kingfisher and pigeon remains uncertain, though the pigeon is believed to have been the only known specimen of the now-extinct Mauke fruit dove.
7. Delcourt’s Giant Gecko

The New Caledonian giant forest gecko holds the title of the largest living gecko, reaching a length of 36 centimeters (14 inches). However, Delcourt’s giant gecko, known only from a partial taxidermy mount, grew to 62 centimeters (2 feet), making it almost twice as large as its living counterpart.
The species was first identified as new in 1986, appropriately named after the herpetologist at The Marseille Museum of Natural History, where it was displayed to the public. Alain Delcourt became seriously interested in the gecko in 1979. Prior to this, the specimen had been in the museum for over a century, with visitors unaware of its importance. No collection or locality data accompanied the mount, but it is believed to have been collected between 1833 and 1869. As no records from that time have survived, this hypothesis seems plausible, although it could date as far back as 1819, when the museum first opened, or as late as 1902, when stricter record-keeping was instituted.
Scientists unanimously agreed that the gecko’s origin lies somewhere in the Pacific. Given the specimen’s location in a French museum, New Caledonia was initially proposed as its habitat. However, due to its resemblance to the brown forest gecko, New Zealand seems a more likely home. This is where cryptozoologists may find interest, as the giant gecko closely resembles the kawekaweau from Maori mythology, described as around 62 centimeters (2 feet) long, “as thick as a man’s wrist,” and a rusty brown color. These creatures were also considered omens of death. Legends about them trace back to Captain Cook’s 1777 voyage, during which a couple of large reptiles were captured but subsequently lost. Whether these reptiles were kawekaweau, giant geckos, or another species remains unclear. In 1870, a Maori chief reportedly saw and killed a live one, but no further sightings occurred until the 1990s.
The mount was briefly sent back to New Zealand as part of the 150th anniversary celebrations for the signing of the Treaty of Waitangi. Renowned biologists, including Dr. Anthony P. Russell and Dr. Aaron M. Bauer, believe the two creatures to be the same. However, until another specimen is discovered, it remains uncertain whether they are correct.
6. Percy Island Flying Fox

As its name indicates, the holotype of this bat was discovered in the Percy Island group off Queensland, Australia. Captain Denham of HMS Herald observed the animal in the late 19th century, though the exact year varies in reports. The timing of its collection is just one point of contention among scientists. Some 19th-century accounts describe the bat as abundant on these islands, while others question whether the specimen even originated there, or if it truly represents a distinct species. Certain researchers speculate that the bat, also referred to as the dusky flying fox, may have been a windblown small flying fox from The Louisiade Archipelago, while the Solomon Islands have also been suggested as a potential place of origin. Interestingly, another bat, the Nendo tube-nosed fruit bat, is known to have come from the Solomon Islands, leading to further uncertainty regarding the dusky flying fox's true origin.
The confusion surrounding the animal’s origin and classification led to its removal from the Convention on International Trade in Endangered Species (CITES) in 2001. The Australian government has since ceased recognizing the bat as a valid species.
In the early 1990s, there were unverified reports suggesting a colony of dusky flying foxes might have been residing on nearby Akens Island, but subsequent searches yielded no evidence. The only known specimen of this bat is a taxidermy mount housed in The British Museum.
5. Luchihormetica Luckae

Though this cockroach was hailed as one of the top new discoveries of 2012, it was actually studied and formally described based on a single specimen collected in 1939.
This cockroach is an anomaly among land animals due to its bioluminescence. Even rarer, its glowing is not intended to communicate or attract a mate, as seen in fireflies, but rather serves to imitate the toxic click beetle in order to avoid being eaten. Additionally, this species is the sole example of asymmetrical bioluminescence, giving it a look reminiscent of a character from Star Wars.
Using technology unavailable seven decades ago, scientists scanned the adult male cockroach and concluded that luminescent land animals are much younger than their marine relatives.
Unfortunately, this cockroach seems to be less resilient than people often think. The region of Ecuador where the cockroach was discovered was ravaged by the Tungurahua volcano in 2010. Combined with the ongoing urbanization of the area, scientists now fear that the cockroach has likely gone extinct. Unless another specimen is accidentally found, this remarkably unique insect will remain a singular discovery.
4. Golden Moles

There are 21 species of golden moles, many of which are endangered. Despite their name and appearance, they are only distantly related to true moles.
Due to their underground habits, these creatures have proven to be quite difficult for scientists to study, with two species being especially elusive. The Somali golden mole (Calcochloris tytonis) is only known from a partial skeleton discovered in an owl pellet in 1964. Visagie’s golden mole (Chrysochloris visagiei) is slightly more accessible. Its type specimen was found in 1950 on an estate in Gouna, South Africa, and named after the landowner. Since no additional specimens have been discovered, despite multiple field expeditions, some believe there may have been a mistake in recording its origin or that the animal was naturally carried there by floodwaters from the Renoster River. The surrounding areas are considered unsuitable for burrowing animals, which lends credibility to these theories.
Given the significant changes to the type locality since 1950 due to agricultural expansion, scientists now suspect that the species may have become extinct. However, Van Zyl’s golden mole (Cryptochloris zyli), which was previously known from a single specimen collected in 1938, was rediscovered with a second specimen in 2003.
3. Lady Gaga Braconid

In 2012, this minuscule insect captured attention and sparked controversy not only because of its name but also due to the methods used to identify it. A female specimen was discovered in Chae Son National Park, Thailand, as part of a three-year survey that covered 25 national parks across Thailand. Hundreds of other species were also uncovered in the survey, and all were described using the technique of “turbo taxonomics”—a form of DNA barcoding that enables the quick identification of newly discovered species. In the past, it could take decades to formally describe a species, but this new approach, which uses a short DNA sequence from the genome, speeds up the process. The method has both supporters and critics.
The insect itself is incredibly small, measuring just 5mm (.1 in), and has been identified as a parasitic wasp. Scientists believe it lays its eggs inside its prey's head, and the larvae devour the host from the inside once they hatch. Lady Gaga has yet to comment on this unusual honor. The reasoning behind the wasp’s name has puzzled many, as there seems to be no clear explanation for it. Some have argued that the name is not “nerdy” enough, while others suggest it’s a playful way to engage a younger audience in taxonomy. The most plausible reason appears to be publicity, and since this wasp, rather than one of the 178 other species found in the same survey, made the headlines, it seems to have worked.
This wouldn't be the only time Lady Gaga's name would be used in scientific discoveries. In October 2012, 19 fern species were named in her honor. In this case, the scientists defended their decision, explaining that Gaga’s advocacy for gender equality made her a fitting figure to have her name associated with these gender-changing ferns.
2. Nechisar Nightjar

This species is known for being represented by an extreme case of a single specimen: a single wing, which inspired its Latin name, solala, meaning 'only a wing.' Unlike the other birds on this list, this one did not fall victim to a Victorian explorer’s firearm, but rather likely met its end after being struck by a car in the Nechisar Plains of Ethiopia. The wing was salvaged from the decaying carcass and brought to the Natural History Museum in London.
Believed to have come from a female or a juvenile male, the wing is noted for being unlike any other nightjar. It features large buff-colored spots and a buffish-white band. Thought to be endemic to the Nechisar Plains, it is considered vulnerable due to its limited range. The National Park where these plains are located no longer enjoys the same level of protection it once did in the 1980s and 1990s. Additionally, illegal settlers in the region caused a fire in 1998 that severely damaged the bird’s habitat.
As with the previous example, there is still hope that more specimens could be located. In 2009, a group of birdwatchers ventured to the region in Ethiopia where the wing was discovered. They likened their expedition to those of Victorian explorers, but their goal was to photograph the bird rather than shoot it. The birdwatchers claimed to have seen a bird with similar markings to the nightjar and remain convinced of their sighting. However, with only blurry photographs as evidence, the mysterious 'only a wing' nightjar continues to live up to its name.
1. Cyclops Long-Beaked Echidna (Sir David’s Long-Beaked Echidna)

Unlike many of the other creatures on this list, scientists hold hope that this species still exists, and it is currently listed as critically endangered rather than extinct by the IUCN. Named after the esteemed British naturalist Sir David Attenborough, this animal is known only from a somewhat damaged specimen, discovered in 1961 in the Cyclops Mountains of Papua New Guinea by Dutch explorers. The specimen now resides at the Leiden Natural History Museum in the Netherlands. This is the smallest species of echidna, all of which are endangered, and it is thought to be endemic to just one mountain peak in the region.
In 2007, researchers discovered fresh tracks and feeding holes, also known as 'nose pokes,' created by the creature. Local hunters also claim to have seen—and likely consumed—the animal as recently as 2005. Since the feeding holes were found at a lower altitude than where the original specimen was discovered, scientists remain hopeful that more individuals might reside higher up the mountain. However, no additional specimens or partial remains have been found.
This species has since received focused attention from EDGE, an initiative aimed at raising awareness about it. Additionally, there is ongoing collaboration with local communities to discourage hunting and consumption of the animal. This conservation effort, launched by the Zoological Society of London, seeks to protect genetically unique species and includes nine other animals, such as the Yangtze River dolphin.
