Nature's most wanted: a blind salamander, a tap-dancing spider, a tree-dwelling kangaroo. A long-beaked echidnaAttenborough's long-beaked echidna is the Earth's oldest living mammal. It lays eggs like a platypus, which hatch in a pouch, like a marsupial. They are native to New Guinea. named after David Attenborough. They are some of the most critically endangered animals on Earth and the hardest to find.

Scientists fear the world is acting too slowly to save these species. The Covid-19 pandemic has delayed a major UN summit on biodiversityBiodiversity is all the different kinds of life you'll find in one area - the variety of animals, plants, fungi, and even microorganisms like bacteria that make up our natural world. Each of these species and organisms work together in ecosystems, like an intricate web, to maintain balance and support life.  by two years. "The longer we wait, the more diversity is lost," warns conservation biologist Alice Hughes.

A UN report in 2019 predicted one million species could disappear, "many within decades", without urgent action. Human activity is degrading the natural world and "biological communities are becoming more similar to each other".

However, there is hope. Intrepid scientists are scouring dense jungles and the deep ocean for lost species. They have found the world's largest bee, the silver-backed ChevrotainA fanged deer-like creature the size of a rabbit. In 2019, it was found in the forests of southern Vietnam. and the Fernandina Giant TortoiseLast seen in 1906, this Galapagos tortoise was rediscovered on Fernandina Island in 2019. . These so-called LazarusIn the bible, Jesus restores Lazarus to life, four days after his death. animals have not been seen for several decades. 

Like the Hills' horseshoe bat, last recorded in 1981. When scientists recently caught up with it in the Rwandan rainforest, they were delighted. "This elusive creature has been flying for forty years, unknown to humans, living this secret life," says biologist Winifred Frick. But can hunting lost bats save the planet?

Scientists argue these rare endemic species help them understand the broader ecosystem. And before we can bring it back from the brink, we need to know "the distribution of, and threats to, a species," says conservationist Barney Long.

He works on the Re:wildThe organisation was founded by actor and environmentalist Leonardo DiCaprio. Scientists have named a newly discovered beetle and a tree after him. project, coordinating the global search for an estimated 2,200 species missing for ten years or more. He says these discoveries are "a powerful antidote to despair."

But is it enough? "A rediscovered species is still in danger of extinction," warns biologist Diogo Verissimo. These tenacious survivors have defied the odds, but their habitats are still under threat. The UN says humans have altered 70% of the land.

Other scientists like R Alexander Pyron argue that "extinction is part of evolution" and we should not try to save these doomed beasts. "They will go extinct one day, and the world will be none the poorer for it."

The last dodo died three hundred years ago, but its reputation lives on as the clueless and clumsy flightless bird destined for extinction. This is unfair, says avian palaeontologist Julian Hume. It was smart, agile and "perfectly adapted to its environment".

But humans introduced invasiveA non-native species that becomes overpopulated and damages its new environment. species like pigs, goats and rats, which disrupted the dodo's ecosystem. So scientists argue habitat conservation is essential and world leaders must approve plans to protect 30% of the Earth's lands and seas by 2030.

The postponed UN conference will be held in China this summer. Brian O'Donnell of the Campaign for Nature says: "there has never been this much support for conservation in history" and what we do next will dramatically affect the survival of life on Earth.

Yes: Rediscovered species show the resilience of nature, faced with the challenges of human activity and climate change. The dedication of researchers to these species can inspire all of us to do more.

No: It is probably too late for these endangered species. They may be exciting and comforting to find in the wild, but the main focus should be on protecting more of the world from human development.

Or... We don't really know. Science is about exploring the unknown and taking risks. These species may help us understand nature, climate change and biodiversity in ways we can not anticipate.