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As Earth’s climate shifts and human activity continues to reshape ecosystems, many plants and animals struggle to survive. In some instances, dramatic population declines lead scientists to declare a species extinct when reliable evidence of its existence disappears for an extended period. Today, there are 856 “missing” species as of 2023 that researchers hope to find again.
When a species goes unseen for years, it’s easy to assume it no longer exists. Yet history shows that many presumed‑lost animals have resurfaced. Often these species maintain only small, isolated populations, which explains why they remained undetected by both locals and researchers for long periods. What’s striking is that several have been absent for decades before their unexpected return.
Indigenous to Myanmar’s Arakan Mountains, the Arakan forest turtle was declared extinct in 1908. It reappeared in Asian food markets toward the end of the 20th century, prompting zoos and aquariums in the United States to launch coordinated breeding and reintroduction programs.
In its natural habitat, the turtle dwells among bamboo and forest understories in western Myanmar. It is largely nocturnal, hiding beneath leaves during hot daylight hours. Threats include habitat loss, illegal pet trade, and hunting. Conservation facilities worldwide have reported successful breeding, with the Tennessee Aquarium giving birth to two hatchlings in 2023.
Known as the world’s largest bee, Wallace’s giant bee can have a wingspan exceeding 2.5 inches. The Indonesian species was thought to have vanished in 1981, but it was rediscovered in 2019 on the island of North Moluccas.
While still the largest bee, it remains rare. Deforestation and human development threaten the trees and termites that serve as its primary food sources. The species also faces risk from wildlife trade, with a few individuals now held in museums and private collections.
Also called the Somali elephant shrew, the sengi is a small mammal with an elephant‑like nose, large eyes, and rounded ears. It vanished from scientific records after 1968, but was rediscovered in Djibouti in 2020, 50 years after its last documented sighting.
Little is known about its behavior; it inhabits rocky dwellings and forages for insects. The species may have existed for over 45 million years, predating other Somali fauna such as zebras and lions. Ongoing research seeks to clarify its population status and ecological needs.
Dubbed the “golden wonder,” this salamander was first described in 1975 in Guatemala. It was not seen again until 2017, with only three confirmed records to date.
The salamander resides in the Cuchumatanes mountains, an area experiencing rapid industrial growth. Deforestation remains its most significant threat, and its elusive nature complicates population estimates.
In 2021, an expedition to Sierra Leone led to the rediscovery of two freshwater crab species. The Sierra Leone crab, first reported in 1955, is notable for its dark purple coloration; only a handful have been found during the 2021 survey. The Afzelius crab, also rediscovered in 2021, had not been recorded for 225 years and appeared in larger numbers than its counterpart.
Both species face habitat loss from logging and agriculture. Two additional freshwater crab species were also described during the same expedition.
Once considered a “living fossil,” the African coelacanth was discovered alive off South Africa’s coast in 1938 after its fossil record suggested extinction over 65 million years ago.
The species can reach 6.5 ft in length and weigh up to 198 lb. It inhabits the eastern African coast between Tanzania and South Africa, including Madagascar. With an average lifespan of about 48 years, it is classified as threatened, primarily due to bycatch in commercial fisheries.
Birds are particularly vulnerable to climate change and human activity. The Antioquia brushfinch, first formally described in 2007 from 1970s specimens, was missing for 47 years before being sighted again in 2018.
Its distinctive rust‑colored crown marks it among Colombian avifauna. Fewer than 50 individuals are estimated to remain in the wild, with ongoing habitat loss from cattle ranching posing a major threat.
This tortoise subspecies was first recorded in 1906 on Fernandina Island, but only a single male was ever seen. Tragically, the specimen was killed by scientists for research purposes.
In 2019, a female tortoise with similar genetics was found, named “Fernanda.” At 50 years old, she may be the sole surviving member of her subspecies, though scientists remain hopeful of uncovering additional individuals.
Despite its parrot‑like appearance, the night parrot is a small, green bird that is nocturnal. Classified as critically endangered, it faces threats from wildfires, introduced predators, and habitat loss.
It was rediscovered in 2013 after being presumed extinct for over a century. Current estimates suggest around 50 individuals persist in western Australia, a hopeful sign following decades of decline.
First identified via fossil records, the Chacoan peccary was found alive in the early 1970s in South America. It resembles a pig, with long, bristle‑like fur ranging from brown to gray.
The species is endangered, largely due to habitat loss from human development, which disrupts access to cacti and natural soil salts essential to its diet. In captivity, it can live twice as long as in the wild, with a lifespan of about 18 years.
Discovered in 1893, this Madagascan chameleon disappeared from records by 1913. It was rediscovered in 2020 after more than a century.
Females are notably colorful when stressed, shifting from green to black, white stripes, purple patches, and red dots. Males typically display lighter green hues. Ongoing research seeks to better understand its ecology and compare it to other Madagascan chameleons.
Found in the Annamite Mountains on the Laos‑Vietnam border, the silver‑backed chevrotain was thought extinct until 2019, when two small populations were located.
Also known as the Vietnam mouse‑deer, it resembles a small deer but is no larger than a rabbit. It is the smallest hoofed mammal on Earth. Research continues to assess its population size, diet, and threats.
