The Protein Time Capsule: How Collagen Outlasts DNA
Meet the Giants: Australia’s Lost Megafauna Trio
The Sahul Surprise: Did Humans Meet These Beasts?
The Limits of Collagen: Why Some Mysteries Remain
The Next Frontier: Hunting the "Marsupial Lion" and Mega-Wombats
Rewriting Extinction: Climate vs. Humans

For decades, the fossilized bones of Australia's megafauna giant marsupials once rovers of the continent have murmured secrets just beyond our reach. Too often, these remains are scattered, degraded, or insufficient to recognize. But now thanks to an unexpected key collagen scientists have opened a fresh window into the past. Three massive extinct species, a hippo-sized wombat, a giant kangaroo, and a clawed marsupial like a prehistoric nightmare have unusual protein markers in their bones, according to a ground-breaking study. This revelation not only clarifies identification questions but also starts the discussion on what actually killed these giants and whether humans had a part in their death.

The Protein Time Capsule: How Collagen Outlasts DNA

When most people consider ancient genetic hints, they picture DNA. But in Australia's hostile, sun-scorched environments, DNA sometimes disappears beyond human comprehension thousands of years ago. Far more robust is collagen, the structural protein keeping bones together. While DNA breaks down in heat and humidity, collagen can withstand tens of thousands of years even in tropical environments where fossils usually vanish into dust.

This durability makes collagen peptide analysis, a technique called ZooMS (Zooarchaeology by Mass Spectrometry), a game-changer. By examining tiny variations in collagen’s amino acid chains, scientists can distinguish between species, genera, and sometimes even individual animals. "Proteins preserve better over longer timescales and in harsher environments than DNA," explains Dr. Carli Peters of the University of Algarve, lead author of the study. "This means we can extract data where DNA has long since vanished".

Meet the Giants: Australia’s Lost Megafauna Trio

The study focused on three extraordinary species, each a relic of a time when Australia’s wildlife was stranger and far larger than today’s:

Zygomaturus trilobus: A monstrous marsupial resembling a "wombat the size of a hippo," weighing up to 700 kg (1,540 lbs). This slow-moving herbivore likely wallowed in swamps, its broad snout adapted for grazing on tough vegetation.

Palorchestes azael: A bizarre, tapir-like creature with retractable claws, a trunk-like snout, and a long, sticky tongue. Weighing nearly a metric ton, it may have reared up on its hind legs to strip leaves from trees.
Protemnodon mamkurra: A hulking kangaroo that moved on all fours, unlike its modern bounding relatives. At 100–150 kg (220–330 lbs), it was a slow, forest-dwelling browser that vanished just as humans arrived in Tasmania.

These species represent families that died out entirely vanishing without descendants making their collagen markers crucial for reconstructing their lost world.

The Sahul Surprise: Did Humans Meet These Beasts?

One of the most tantalizing questions is whether early humans encountered these creatures. The study reveals that Protemnodon mamkurra survived until at least 43,000 years ago around the time humans first crossed into Tasmania via the Sahul land bridge (which connected Australia, New Guinea, and Tasmania).

"Imagine being among the first humans to step onto this continent and seeing a two-ton wombat or a kangaroo that walked like a bear," says Professor Katerina Douka, senior author of the study. "It would have been a world of monsters".

But was it humans or climate that wiped them out? The debate rages on. Some sites, like South Walker Creek in Queensland, show megafauna surviving until 40,000 years ago, long after human arrival suggesting environmental shifts, not hunting, drove their extinction.

The Limits of Collagen: Why Some Mysteries Remain

While ZooMS is revolutionary, it has its quirks. The team could distinguish Protemnodon from living kangaroos, but Zygomaturus and Palorchestes shared nearly identical collagen markers. "Collagen evolves extremely slowly," explains Peters. "For now, we can separate them at the genus level, but not species".

This means some fossil fragments may never be fully identified unless future research uncovers more refined protein signatures. Still, even genus-level identification is a leap forward for Australia’s sparse fossil record.

The Next Frontier: Hunting the "Marsupial Lion" and Mega-Wombats

Studying is just the beginning. Two of Australia’s most iconic megafauna Diprotodon (the largest marsupial ever, at 2,800 kg) and Thylacoleo carnifex (a leopard-sized "marsupial lion" with bone-crushing teeth) still lack collagen markers.

"These were apex predators and mega-herbivores," says Peters. "If we can find their peptide fingerprints, we might finally solve why they disappeared".

Rewriting Extinction: Climate vs. Humans

The collagen breakthrough adds fuel to the fiery debate over Australia’s megafauna extinction. Some argue humans hunted them to oblivion; others point to climate shifts. At Naracoorte Caves, a fossil-rich site now dated to 1.34 million years old, megafauna thrived until sudden environmental collapse.

Meanwhile, South Walker Creek’s megafauna vanished amid worsening droughts and wildfires without clear evidence of human involvement. The new collagen data could finally tip the scales in this decades-old mystery.