If you’ve ever stared at a woolly mammoth skeleton in a museum and thought, “Why can’t we just Ctrl+Z extinction?” you’re not alone. A growing number of researchers are trying to do exactly that through de-extinction projects that blend genetics, conservation biology, and just a little bit of sci-fi energy.
From fluffy ice-age giants to marsupial “tigers,” scientists are asking a bold question: Should we bring some species back, not just because we miss them, but because they might help repair damaged ecosystems? Below are 10 extinct animals that researchers most often talk about revivingand the scientific (and ethical) roller coaster that comes with them.
What Is De-Extinction, Anyway?
De-extinction is a catch-all term for efforts to recreate extinct species or close ecological stand-ins using tools like DNA sequencing, gene editing (think CRISPR), selective breeding, and cloning. Instead of magically reassembling a Jurassic Park–style dinosaur, real-world projects usually aim to edit the genome of a living relative until it closely resembles the extinct animal’s DNA, then raise that edited embryo in a surrogate parent.
Groups like Revive & Restore and Colossal Biosciences are already pouring money and brainpower into de-extinction attempts involving mammoths, passenger pigeons, the thylacine, and the dodo. Their goal isn’t just to wow the public; they argue that some lost species were “ecosystem engineers” whose return could help restore forests, grasslands, and island habitats.
But it’s controversial. Critics worry about animal welfare, unintended ecological consequences, and the possibility that shiny resurrection projects might distract from saving endangered species that are still clinging to life. Keep all of that in mind as we tour the de-extinction “wish list.”
Top 10 Extinct Animals Scientists Want to Bring Back
1. Woolly Mammoth
If de-extinction had a mascot, it would be the woolly mammoth. These shaggy, ice-age elephants once roamed the tundra of Eurasia and North America, shaping grassland ecosystems as they trampled, grazed, and fertilized their way across the frozen landscape. They disappeared roughly 4,000 years ago, thanks to a mix of climate warming and human hunting.
Because mammoth carcasses have been found frozen in permafrost, scientists have recovered fragments of DNA good enough to sequence entire genomes. Colossal Biosciences and other teams are working to edit Asian elephant DNAits closest living relativeso the animals gain mammoth-like traits such as thick fur, subcutaneous fat, and cold-adapted blood.
The pitch is that “mammoth-like” elephants could help restore Arctic grasslands, potentially locking more carbon in the soil and slowing permafrost melt. Whether that plan will workor just give us very expensive, very confused fuzzy elephantsis still an open question.
2. Dodo
The poor dodo has become a punchline for extinction, but scientists are trying to give this flightless bird from Mauritius a second act. Dodos vanished in the 17th century after sailors, invasive animals, and habitat destruction hit the island all at once.
Researchers have now sequenced the dodo’s genome from preserved bones and museum specimens. Colossal Biosciences is working with paleogenomic experts to edit the DNA of the Nicobar pigeona close living relativeso that future birds carry dodo-like genes. The long-term dream is to reintroduce them to protected, predator-free areas of Mauritius.
Supporters say it would be a powerful symbol of ecological restoration. Skeptics counter that island ecosystems are extremely delicate and that any reintroduction would have to be slow, controlled, and reversible.
3. Thylacine (Tasmanian Tiger)
The thylacine, or Tasmanian tiger, might be the most mourned marsupial in history. This dog-sized predator with tiger-like stripes was hunted to extinction in the early 20th century after being (often unfairly) blamed for livestock losses. The last known individual died in a Tasmanian zoo in 1936.
Today, a partnership between Colossal Biosciences and a University of Melbourne lab is attempting to bring the thylacine back. Scientists have built a near-complete genome and are editing the DNA of a tiny carnivorous marsupial, the fat-tailed dunnart, to match thylacine genes. The plan is to eventually grow embryos in marsupial surrogatesbasically turning a modest little dunnart into a stand-in for a long-lost apex predator.
Why bother? Researchers argue that Tasmania has no native predator that fills the thylacine’s former niche. A carefully managed reintroduction, they say, might help rebalance local ecosystemsif we can figure out how to raise and release them humanely.
4. Passenger Pigeon
Once upon a time, passenger pigeons darkened North American skies in flocks so dense they reportedly took hours to pass overhead. These birds shaped eastern U.S. forests by stripping trees of seeds and branches, opening patches of ground that other plants and animals relied on. We then hunted them into oblivion by 1914.
Revive & Restore has long treated the passenger pigeon as a flagship de-extinction candidate. Scientists have sequenced DNA from museum specimens and compared it with the genomes of band-tailed pigeons, the closest living relatives. The idea is to gradually edit band-tailed pigeon DNA until their descendants behave and function ecologically like passenger pigeons, even if they aren’t genetic clones.
In theory, these “neo-pigeons” could be reintroduced to managed forests to restore some of the ecological chaosyes, chaosthat once made those ecosystems more diverse.
5. Heath Hen
The heath hen is a lesser-known but fascinating candidate. This booming, puffed-up prairie bird once lived along the eastern U.S. coast and may have been the “turkey” served at early colonial Thanksgivings. Overhunting and habitat loss drove it to extinction in 1932, when the last known male, nicknamed “Booming Ben,” vanished on Martha’s Vineyard.
Revive & Restore has considered a heath hen revival using its close relative, the greater prairie chicken, as a genetic starting point. By tweaking DNA and selectively breeding for heath-hen-like traits, scientists hope to eventually release ecological stand-ins that can help maintain rare coastal grasslands.
It’s less glamorous than a mammoth, but the conservation payoff for restoring a lost grassland bird could be huge.
6. Aurochs
The aurochs was the massive, wild ancestor of modern cattle. These horned beasts once roamed Europe, North Africa, and parts of Asia before disappearing in the 17th century due to hunting and habitat loss. Because aurochs are literally the forebears of today’s cows, their DNA survives scattered through many cattle breeds.
Instead of high-tech gene editing, several European projects are using “breeding back”selectively crossing cattle that retain aurochs-like traits in hopes of recreating something close to the original. The goal is to reintroduce hardy, wild-grazing cattle to certain landscapes, where they could help maintain open woodlands and grasslands.
From a practical standpoint, the aurochs is one of the easiest “extinct” animals to approximatebut that doesn’t completely solve ethical questions about releasing tough, semi-wild bovines into modern Europe.
7. Quagga
Imagine a zebra that gave up halfway through putting on its stripes: that’s the quagga. This subspecies of plains zebrastriped in front, brown in backonce lived in South Africa but was hunted to extinction in the 19th century. Because it’s a zebra variant rather than a completely separate species, modern zebras still carry bits of quagga DNA.
The Quagga Project in South Africa has been selectively breeding zebras that show quagga-like striping and coloration. It’s not gene editing, but it is a kind of de-extinction through selective breeding. The plan is to eventually restore herds that fill the quagga’s former ecological role in grasslands and savannas.
8. Pyrenean Ibex (Bucardo)
The Pyrenean ibex, or bucardo, was a wild goat that lived in the mountains between Spain and France. It officially went extinct in 2000 when the last known female, Celia, was found dead under a fallen tree. Scientists preserved tissue from Celia, and in 2003 they managed to clone hercreating the first de-extinct animal in history. The kid died shortly after birth from lung defects, but it proved that cloning an extinct species was technically possible.
Although efforts to continue the project stalled, the Pyrenean ibex still appears on many de-extinction “most wanted” lists. Cloned or gene-edited ibex could potentially help restore overgrazed or depopulated mountain ecosystems, though researchers would have to work through serious welfare issues before trying again.
9. Gastric-Brooding Frog
If you like your de-extinction with a side of weird, meet the gastric-brooding frog. Native to Australia, this frog swallowed its fertilized eggs and literally raised tadpoles in its stomach, shutting off acid production until it burped out fully formed froglets. Both known species went extinct in the 1980s, likely due to habitat loss and disease.
Australian scientists have used preserved tissue and cloning techniques to make early-stage embryos that carried some gastric-brooding frog DNA, in a project nicknamed “Lazarus.” While none survived to adulthood, the work suggested that, at least in principle, this bizarre reproductive strategy might not be gone forever.
Beyond the novelty factor, bringing back this frog (or something close to it) could offer insights into controlling stomach acidresearch that might one day benefit human medicine.
10. Moa
The moa were giant, flightless birds from New Zealand, some species reaching over 10 feet tall. They were wiped out roughly 600 years ago after humans arrived and hunted them heavily. Today, moa bones and preserved DNA fascinate scientists, who see them as key to understanding how island ecosystems functioned before major human impact.
Colossal Biosciences recently announced plans to resurrect the South Island giant moa by editing the genomes of its closest living relativeslikely emus or tinamousand raising hybrid birds in fenced reserves. The company argues that moa-like birds could help restore native vegetation and cultural connections in partnership with local communities. Critics worry about how “authentic” these hybrids would be and whether resources would be better spent saving endangered birds that are still here.
Should We Really Bring These Animals Back?
On paper, de-extinction hits all the right emotional notes: scientific heroics, environmental redemption, and the thrill of seeing animals we only know from paintings and skeletons. But scientists emphasize that every project raises tough questions:
- Animal welfare: Gene editing, cloning, and experimental breeding often involve failed pregnancies and short-lived offspring. How much suffering is acceptable in the name of restoration?
- Ecological impact: Ecosystems have changed since these species disappeared. Their niches may be goneor filled by something else.
- Opportunity cost: High-profile de-extinction efforts can attract funding, but critics worry they may pull attention away from protecting endangered species that can still be saved.
Many experts argue that the most responsible path is “functional de-extinction”: creating animals that behave like lost species and help restore ecosystems, without insisting on perfect genetic replicas. In other words, it might be less about resurrecting a celebrity species and more about rebooting its ecological job description.
What De-Extinction Means for the Rest of Us
Even if you never stand in front of a living mammoth, de-extinction research is already reshaping conservation. Techniques developed for extinct specieslike advanced genome editing, artificial wombs, and better cloning methodscan also help endangered animals such as rhinos, ferrets, and rare birds survive.
The deeper message is uncomfortable but important: humans drove most of these species to extinction. De-extinction won’t erase that history, but it forces us to confront what kind of future we want. Do we treat these technologies as a backup plan, or as a warning to finally stop pushing species over the edge?
Living With the Idea of Extinct Animals Returning: A 500-Word Thought Experiment
So what would it actually feel like to live in a world where some of these animals returnat least in modified, carefully managed form?
Picture this: It’s a chilly morning in a rewilded Arctic reserve. Tourists stand a safe distance away on a raised platform, bundled in parkas and clutching hot coffee. Out on the tundra, a herd of shaggy, mammoth-like elephants wanders through the snow, scraping away drifts with their tusks to reach tough grasses below. The park guide explains that their grazing keeps shrubs from taking over, helping preserve open grasslands and reflecting more sunlight back into space. It’s a climate solution that also happens to look like a live-action Ice Age movie.
Meanwhile, halfway around the world, birdwatchers on Mauritius line up at dawn along a quiet forest path. Instead of scanning for an extremely rare endemic species, they’re invited to watch the first generation of dodo-like birds cautiously explore a predator-free sanctuary. The birds don’t quite match the illustrations in old natural history books, but they’re close enough that you can feel history shifting a little under your feet. Their presence makes it harder to say, “Once something is gone, that’s it.”
On Tasmania, conservation teams might one day drive slowly along back roads at night, scanning the bush with thermal cameras, hoping to catch a glimpse of a collared thylacine weaving through the undergrowth. Each animal’s movements would be monitored almost obsessively, with emergency plans ready if anything starts to go wrongeither for the species or for the ecosystem around it. Local communities, farmers, and Indigenous groups would be deeply involved, negotiating how to live with a predator that’s both a symbol and a real, sharp-toothed animal.
At the same time, a rewilded forest in the eastern United States could echo with the sound of enormous flocks of pigeon-like birds taking off at once. Forest managers, who currently rely on chainsaws and controlled burns, would factor in the behavior of these birds as another tool for shaping habitat. They’d also have to deal with the less romantic side: droppings, noise, crop concerns, and the strange feeling of adjusting to a sky that suddenly seems very crowded.
Living in this world would demand a new kind of flexibility from us. We’d need to accept that some “brought back” animals are approximations, not perfect copies. We’d also have to develop policies and ethics for species that are simultaneously wild and highly engineered.
Most importantly, everyday peoplenot just geneticistswould have a say. Community meetings might debate whether a valley is ready for aurochs-like cattle. Schoolkids might write essays on whether it’s fair to raise frogs that incubate their babies in their stomachs. And social media would absolutely explode the first time a clear video of a reintroduced thylacine hit the internet.
In that sense, de-extinction is less about time travel and more about responsibility. If we gain the power to bring back even a handful of species we erased, we also take on the responsibility to care for themand to make sure the ones still here never need a resurrection project of their own.
