Unlocking secrets deep inside the world's most precious specimens

Australia Broadcast Center

11-07-2025

It was a coup, years in the making.
After lengthy negotiations, the custodians of the 13 youngest preserved Tasmanian tigers in existence had all agreed for their specimens to be studied by a team of scientists in Melbourne.
Nine from museums across Australia and four from Charles University in Prague, which had been in the institution's zoology department for more than a century but had only recently been rediscovered.
It was incredibly rare for these preserved creatures to leave their museums. The Tasmanian Museum and Art Gallery placed such high value on their decades-old specimens, it had a curator personally escort them by plane across the Bass Strait.
Convincing the museums to release the Tasmanian tigers relied, in no small part, on the novel way the researchers promised to analyse them. Two of the three Tasmanian tiger joeys held in the Museums Victoria collection. ( ABC News: Margaret Burin )
Instead of the age-old method of slicing the creatures open to reveal their internal structure and ultimately destroying the specimen, they would be examined using a process known as computed tomography scanning, or CT scanning for short.
A staple of the medical profession since the late 70s for diagnosing disease and injury, the X-ray technology is now being increasingly used in museums and universities to look inside the creatures and objects filling their collections.
For example, researchers have scanned tiny meteorites to look back deep in time for ancient minerals from the formation of the solar system, while others are using the technology to better understand the future and predict how a changing climate will impact animal habitats.
In the case of the Tasmanian tiger, it provided an incredibly detailed — and unexpected — view inside the tiny creatures' skin, through to its skeleton and organs inside.
This is specimen A930 from the Tasmanian museum.
The nine-week-old, male Tasmanian tiger joey, measures around 20 centimetres.
From the exterior, you can see his developing claws and footpads. The species' distinctive stripes have not yet developed.
But it's underneath the skin, where the power of the CT scan shines.
Using a process known as segmentation, researcher Axel Newton was able to identify the tiger's vital organs including its heart, lungs and brain.
Even more intricate features like the windpipe and the bronchiole — a tiny web of air tubes inside the lungs — are visible.
The detail in the skeleton allows for precise measurements.
The scans showed the young thylacines at five different stages of their early development, giving the team of scientists, and the world, a never-before-seen blueprint how a baby Tasmanian tiger would have matured inside its mother's pouch.
So clear, in fact, were the scans that the team noticed something peculiar. Two of the specimens (one is highlighted here), which looked almost identical to the other on the outside, were not Tasmanian tigers.
One giveaway, identified in the scans, was that the skeletons had a pair of bones in the pelvis not found in the Tasmanian tiger. The scientists determined they were likely to be quolls or Tasmanian devils.
The discovery reduced the total number of known pouch young Tasmanian tigers in existence from 13 to 11 and wiped millions of dollars off the value of the Tasmanian Museum and Art Gallery's collection.
But for professor Andrew Pask, an epigeneticist from the University of Melbourne and one of the team members involved in the 2018 project, it highlighted just how powerful CT scanning could be.
"It was absolutely magical, to be able to really peel back and start to have a look at all of that incredible data that you can see when you can pick out every single tiny little facet of bone," he said.
On a video call to discuss the research, Professor Pask began by showing off some of his other work: side-by-side CT scans of embryonic mouse penises. He is investigating the effects of microplastics and chemicals on male infertility. Despite being minuscule, the scans reveal stark differences in the test subjects on display.
Before delving too deep into what this could mean for the human race, the conversation hook turns onto another of his projects — bringing the thylacine back from extinction. He's using CT for that too.
The latest use case was scanning the teeth of a specimen to pinpoint the exact location of its root so they could drill a microscopic hole into it to extract DNA.
The results were so good, Professor Pask said, the museum has already offered to get him more teeth.
One reason why museums are warming to the idea of having their collections, even the most prized items, blasted with X-rays is that they often receive an extremely high-resolution, three-dimensional copy in return.
Researchers can access them whenever they please and the museums can also use them for educational purposes. The models can be 3D printed and put on display for the public to see and touch and connect with an extinct Australian marsupial.
"It's just this incredibly valuable resource that will live on forever," said Professor Pask who at one point reached across his desk and pulled into view his very own 3D printed Tasmanian tiger.
"I've got a box of them," he said. How it works
CT scanners work by capturing X-ray images of an object.
But instead of stopping at just one image, like you would to see a broken bone inside a body, they capture hundreds or sometimes thousands of images of an object from all different angles.
The X-rays can then be fed into an algorithm that assembles them into a three-dimensional, digital model — innards and all.
On the fourth floor of the geography, earth and atmospheric sciences wing at the University of Melbourne, deep in a rabbit warren of white walls and fluorescent lights is a small, nondescript laboratory.
If it weren't for the various radiation warnings, it could be any one of the other hundreds of rooms in the building.
But inside, flanked by an array of high-powered computers and monitors, is a million-dollar micro-CT scanner.
Unlike CT scanners in hospitals, which can image an entire human body albeit at a relatively low-resolution, the micro versions are designed to scan objects as small as 1 millimetre in diameter and can distinguish features smaller than a single red blood cell.
In a regular CT scan in hospital theX-ray emitting tube slowly moves around the human inside. In a micro version, the specimens sit on a spindle and are rotated a fraction of a degree while the x-ray tube stays put. Dr Black says he has used this micro-CT scanner to help in 30 different fields of scientific study. ( ABC News: Margaret Burin )
Scientist and CT specialist Dr Jay Black is the machine's operator. He is a "superstar" of micro-CT scanning, according to a number of his colleagues interviewed by the ABC.
As a result, Dr Black is a man in demand. He estimates he's worked across 30 different research fields.
He has teamed up with researchers to study minuscule spider brains to understand how they're being affected by urban light. He has scanned samples from mysterious stone jars believed to be burial sites in Laos to help date and understand where the material came from. And, he also worked on the Tasmanian tiger joeys.
On the day the ABC visited, the scanner was loaded with a small, clear tube housing a marble-sized meteorite. Researchers have used CT scanning to help identify areas inside space rocks like the one on display that could contain ancient solids known as calcium-aluminium rich inclusions — the oldest material ever identified. A small meteorite is loaded into the micro-CT scanner at the University of Melbourne. ( ABC News: Margaret Burin )
"It's amazing, almost every week I have people contacting me from new research fields," Dr Black said.
Researchers are increasingly turning to specialists like Dr Black because of the extreme detail he can get in the scans. The machine in his lab can capture images at a resolution of 1 micron or 0.001 millimetre.
That level of detail has been a game changer for Dr Jane Melville, a taxonomist and evolutionary biologist who worked with Dr Black to map minute differences between Australian lizard species.
In 2019, Dr Melville and her team used micro-CT scans to analyse the skulls of vulnerable grassland earless dragons.
Including this one that was found in a man's freezer in Bathurst, New South Wales.
To the eye, the differences between tiny lizard skills are largely indistinguishable. But by combining these extremely high-resolution 3D measurements with genetic analysis, Dr Melville was able to detect distinct differences.
Prior to their research, these specimens were all classified as the same species.
In their final paper, Dr Melville's team found they were, in fact, four distinct species of earless dragons.
This discovery that has aided conservation efforts of the grass-dwelling lizard, which has been hit particularly hard by urban expansion. In 2023, the critically endangered Victorian grassland earless dragon was spotted for the first time in half a century.
Without CT scanning, measuring the differences between the lizards with such precision would have been near impossible.
"The old style is you get a museum specimen and some calipers and you measure head length and head width and things," Dr Melville said. "But with CT scans you can do that much more accurately, you can do it on the bones and you can do it without damaging these precious museum specimens." Dr Jane Melville studies a preserved earless dragon. ( ABC News: Margaret Burin ) A preserved earless dragon lizard specimen from the Museums Victoria collection is examined under light. ( ABC News: Margaret Burin )
At 11am on a Thursday, the grand foyer of the Melbourne Museum is already jammed packed with preschoolers bouncing from toe to toe as they prepare to meet their fossilised dinosaur idols.
Just beyond the fervour, and down a lift is one of the engine rooms of the whole operation — the wet collection store.
Here, rows and rows of lizards, snakes, fish and miscellaneous critters, float preserved in jars of ethanol. Two of the three Tasmanian tiger joeys in the Museums Victoria collection are here. There's even a shark or two inside giant skip bins at the entrance. Dr Melville looking through the wet specimen collection at Museums Victoria. ( ABC News: Margaret Burin )
When scientists, like Dr Melville, want to study a specimen they come here. But technology is changing that.
Museum collections are, by design, open to all researchers to access to conduct research. But there can be challenges gaining access at times.
Researchers can apply to visit the museum to study items in the collection, but travel can be costly.
Specimens can be posted in the mail, but museums may be reluctant to do that for rare and delicate items.
If a researcher needs to see inside a creature, that can be another road block because of the irreparable damage it would cause. Hundreds of taxidermy animals fill the mounted collection at Museums Victoria in Carlton. ( ABC News: Margaret Burin )
But if a specimen is scanned in 3D, it can be placed online and shared with the entire world, removing almost all barriers to access.
Dr Christy Hipsley, another member of the Tasmanian tiger research team who has also worked with Dr Melville, started using micro-CT scanning more than a decade ago while working at Berlin's Museum of Natural History.
She sees CT as a way of democratising access to the hundreds of millions of specimens stored in the world's museum collections — that together tell the story of life on Earth.
"The idea and the goal is to have a single standardised repository (for CT scanned data) like we have for DNA," Dr Hipsley said referencing GenBank — a publicly accessible database of the world's DNA and genetic sequences.
In 2024, a collection of natural history museums in the United States joined together to scan and publish 13,000 vertebrate specimens from their collections including snakes, frogs, lizards and even a whale.
The humpback specimen was so large it had to be meticulously disassembled and scanned bone by bone before being pieced back together.
But having so much data presents its own problem: how to get meaningful insights from a lifetime of information, when the file size for a single scan can stretch into the gigabytes.
Dr Jane Melville is currently looking at this very problem.
She's involved in a project that's looking to use machine learning to analyse, sort and measure hundreds and thousands of tiny fossils collected from the base of caves across South Australia, Victoria and Queensland.
Dr Melville is hoping the project could help scientists understand how changing environments have impacted creatures, so that they can make better predictions about how climate change will affect them in the future.
"At the moment I think when governments are conserving land for species it's a very static thing. They're thinking, 'oh they're here now, that means they'll always need to be here'." she said.
"But if the climate's changing species actually change their distributions, they move. And so I think we need to have a more dynamic outlook on conserving environments and land for species because under climate scenarios in the future, it's going to change."
Notes about this story:
The CT scan data for the Tasmanian tiger research is publicly available. It can be found in the research paper, Letting the 'cat' out of the bag: pouch young development of the extinct Tasmanian tiger revealed by x-ray computed tomography.
The segmented organs were supplied by Dr Jay Black from the Melbourne Trace Analysis for Chemical, Earth and Environmental Sciences (TrACEES) Platform, courtesy of Axel Newton.
Dr Jane Melville supplied the 3D mesh files for the earless dragon.
The data from the US Natural History museums is publicly available in the The oVert Thematic Collections Network on the Morphosource website . Posted 14m ago 14 minutes ago Fri 11 Jul 2025 at 7:00pm