The last one died of neglect. On a cold September night in 1936, the final captive thylacine — a striped, dog-shaped marsupial sometimes called Benjamin — died at the Beaumaris Zoo in Hobart, reportedly locked out of its sheltered den and exposed to the elements. With it, the species was gone. Australia would not formally declare the Tasmanian tiger extinct until 1986, fifty years later. And in the decades between that lonely death and that paperwork, people kept seeing it.

First, the proof of what was lost, because this is not a creature glimpsed only in blurry legend. The thylacine is one of the best-documented extinct animals on Earth. There are preserved specimens in museums, skeletal mounts, pelts, and — most hauntingly — about ten surviving film clips of living animals. The longest and clearest, shot by naturalist David Fleay at the Hobart zoo in 1933, shows the animal pacing its enclosure, yawning its impossibly wide jaw, lying in the sun. Australia's National Film and Sound Archive has restored and re-released this footage, and it has since been colorized. You can watch a verified-extinct apex predator move and breathe. That is the strange power of the thylacine: we have its corpse and its home movies, and people still report it alive.

The sightings are not a fringe rumor; they are an archive. Researchers have compiled comprehensive databases by combing official government files, museum records, published reports, newspaper morgues, and contemporary correspondence — and the result runs to hundreds of post-1936 reports from Tasmania and, more contentiously, mainland Australia. Crucially, some of these reports sit in government hands. Tasmania's environmental authority continued to log unconfirmed thylacine sighting reports into recent years; reporting reflected an official tally of multiple such reports between 2016 and 2019, with one of the most recent logged in early 2018. These are not all cranks. Among the reporters over the decades are park rangers, trappers, and rural Tasmanians who knew the local fauna cold.

Scientists have actually tried to do math on the question, and the result is more interesting than a flat "no." Researchers including Barry Brook and colleagues built statistical extinction models that ingest the full sighting record — weighting reports by credibility — and asked when the species most likely truly vanished. The analyses generally push the probable extinction date past 1936, into at least the 1940s–1960s, meaning the animal very likely survived in the wild for years or decades after its "last" captive died. One widely discussed model, working from the densest cluster of higher-quality records, could not statistically rule out persistence remarkably late. That is not proof of a living thylacine. It is a peer-reviewed admission that the official 1936 endpoint was wrong, and that the door stays slightly ajar.

Now the skeptical reading, because it has to be stated cleanly. Tasmania is rugged, but it is not boundless, and in nearly a century of cameras, hunters, roadkill surveys, and now ubiquitous trail cams and smartphones, not one carcass, not one unambiguous photograph, not one scrap of verifiable DNA from a living animal has surfaced. Extraordinary claims need physical evidence, and an undisputed living thylacine would produce some. Many sightings are honestly mistaken — at dusk, a mangy fox, a feral dog, or a spotted-tail quoll can read, to a hopeful eye, like a striped ghost. The rational default remains that the thylacine is extinct.

Then there is the plot twist that makes the whole question newly serious: someone is trying to build one. A genetics team led by Professor Andrew Pask at the University of Melbourne's TIGRR Lab, partnered with the U.S. de-extinction firm Colossal Biosciences, is working to reconstruct the thylacine genome and engineer it into a living relative, the dunnart. They have sequenced and assembled thylacine DNA from preserved specimens and reported progress in growing marsupial embryos in the lab. Whether you call the eventual result a true thylacine or a striped facsimile, the science is real and funded and underway.

Which leaves the unresolved question hanging in two directions at once. Did the Tasmanian tiger really die out in the 1930s, or did it slip quietly through the wild margins of Tasmania for decades while officials filed its sightings and ignored them? And if a lab succeeds in stitching one back together from museum tissue, what exactly will be standing in that enclosure — the animal we drove extinct, or a new creature wearing its stripes? The thylacine's defining trait was always that it refused to be a closed case. It still is.