Have you ever wondered about the footsteps of our ancient ancestors? Picture this: lush, remote islands in the Riau archipelago off the coast of Sumatra, where the secrets of human evolution may lie buried beneath the earth. Thanks to groundbreaking research funded by National Geographic Grant NGS-59859R-19, we’re getting closer to unlocking the mysteries of our past.

Between May 22nd and June 10th, 2023, our team of scientists, hailing from both Australia and Indonesia, embarked on a journey to explore the islands of the Riau archipelago. Our mission? To hunt for ancient human fossils using cutting-edge remote sensing and modelling techniques.

Imagine peering through the lens of technology to map out the ancient pathways that Homo erectus and other large mammals once traversed through Sundaland, a landmass connecting Southeast Asia to Java. Through detailed modelling, our results pinpointed the Riau Archipelago as a promising hotspot for exploration, where hidden clues to our evolutionary past might be waiting to be unearthed.

Our adventure began with a survey of several islands, each holding its own geological tale. Batam, with its striking red, yellow, and white clay outcrops, revealed layers of sediment steeped in history. From weathered granitic deposits to evidence of tectonic activity etched into the landscape, Batam whispered tales of epochs gone by.

As the expedition continued west to Karimun, the terrain shifted, offering a glimpse into a different geological narrative. Here, granite outcrops mingled with coarser sands and gravels painted a picture of a land shaped by relentless weathering. Amidst the rugged beauty, the soil hinted at a story of acidity unsuitable for preserving fossils, reminding us of the challenges inherent in unravelling ancient mysteries.

Heading southwards, Kundur beckoned with its metamorphosed outcrops, offering a glimpse into the island’s deep geological history Amidst the rocky terrain, a standing stone stood as a silent sentinel, marking a milestone in the archaeological record of the Riau archipelago.

Bintam held its secrets close, with rhizoliths (plant root fossils) peppering the landscape and rare channel deposits hinting at a dynamic past. Yet, despite the tantalising clues, the elusive fossils remained out of reach, reminding us of the delicate dance between preservation and time.

Singkep and Lingga, with their mountainous landscapes and dense vegetation, teased with fragments of pottery and artifacts scattered among weathered clays. Here, the challenge lay not only in the rugged terrain but also in the scarcity of suitable raw materials for crafting tools. This stands as a testament to the resilience of our ancestors in the face of adversity.

As the expedition drew to a close, one thing became clear: while the journey may not have led to the discovery of ancient vertebrate deposits or early hominin presence, it offered invaluable insights into the preservation potential of Southeast Asian islands. From unforgiving geology to the urbanised landscapes of today, each island whispered a tale of resilience and adaptation, reminding us of our shared journey through time.

As we ponder the footsteps of our ancient ancestors, let’s not forget the lessons hidden within the Earth. For in the untamed wilderness of Southeast Asia, the echoes of our past reverberate, waiting to be heard by those who dare to listen.

Many years ago, I was invited to the South Australian Museum’s Palaeo Week. I’m not sure if the museum still runs it, but it was amazing: a week-long celebration of all things palaeontology. South Australia has some most brilliant and world-class palaeontological resources, from the incredible Ediacaran biota through to the World Heritage Naracoorte Caves.

My job at Palaeo Week was simply to talk to members of the public about how wonderful fossils are. An easy job, right!

When I arrived at the Museum, I was led out to a big marquee that was setup behind the main galleries. There were tons of folk in there keen to learn more about the exhibits and fossils around them.

I took my place towards the back of the marquee and started chatting with various members of the public. And that’s where I met Professor Flint.

Professor Flint

I had never heard of the Professor before. He was a loud Scotsman who bellowed and cried the virtues of palaeontology. He was also one of the experts that the Museum had appointed for the week. I was blown away by his knowledge, the way that he engaged the public, and how he made science so fun.

I later found out that the Professor was the alter ego of Michael Mills from Heaps Good Productions. Michael is a most gifted science communicator. Not a research scientist per se, but he has a voice that can deliver extremely complex scientific ideas, information and theories to the public (and especially kids) in a way that makes it all so accessible.

Michael, or I should say, Professor Flint, is also an incredible performer. He writes children’s songs not only about palaeontology, but AUSTRALIAN palaeontology, and delivers it in a way that inspires and educates his young audiences.

I got to know the Professor on that trip, and stayed in contact with him over the years.

Planting the seed

Fast forward to 2014 and I ran into Michael again, this time in Brisbane when we went out to dinner with some friends from the Queensland Museum. Michael (and Professor Flint) was up in Queensland doing some science engagement activities. It was a great night catching up, talking palaeo and reminiscing about old times.

During the evening, Michael said to me that if I was ever interested in writing a song for the Professor, or at least suggesting some ideas, that he would consider adding it to his repertoire. Now that got me thinking!

When I was a kid, I played trombone in my primary school’s concert band… which I hated! But when I was a little bit older, I got more into music, and played bass guitar and keyboards (somewhat poorly) in a cover band. I’m not sure that I would even consider myself a ‘musician’, but that little kicker from Michael inspired me to hammer out some lyrics for a new song.

I got home and started thinking about what I could write about. I eventually settled on a song about an extinct koala from Australia that my colleague Scott Hocknull and I had described in the scientific literature a few years beforehand.

We named it Invictokoala monticola, which translates as the ‘Invincible koala from the mountain’. The original fossil was found at Mt Etna (hence the species name), just outside of Rockhampton in central eastern Queensland. It dates to around 300,000 years ago.

What is really special about Invictokoala though is that it appears to have been a rainforest-adapted koala. The fossil record previously suggested that koalas became extinct from rainforests during the Miocene around 10-12 million years ago, so for it to turn up so recently in geological time was quite unexpected.

The song itself is a ballad about Invictokoala and why it went extinct. We suspect it was related to significant habitat loss associated with a major shift towards drier conditions.

I drafted up the lyrics and then sung it into my computer (again, very poorly), before emailing it off to Michael.

Michael got back to me in a day or two thanking me. I didn’t really expect to hear anything more, but was then bowled over to receive a message from the Professor himself about a week later: he had tweaked the lyrics a tad, added music to the track, then re-recorded it… he made it incredible!

The final song

I was amazed and so chuffed when the song was added to Professor Flint’s second album, Dinosaurs Amongst Us, released in December 2016. If you haven’t done it yet, you can download it from iTunes, CD Baby, and Amazon, among other websites. You can even listen to it on Spotify.

But even more excitedly, I received a Twitter notification from the Professor just yesterday. Our song, Invictoooookoala, will be performed LIVE for the first time at Flint’s weekend concert, Picnic With The Dinosaurs!

The concert kicks off at the Adelaide Botanic Garden in the early afternoon of Sunday, December 3^rd 2017. It’s a free concert, but be sure to register for your tickets here.

 

*DISCLAIMER* I receive $0 from proceeds towards the Professor’s albums. But please, please, please, I implore you to download it, not just to support Michael Mills and Heaps Good Productions, but to inspire a new generation of young Aussie kids in the virtues of Australian palaeontology, and Science, more broadly.

My team and I have just had a new study published that that looked at the question of migration in a species of giant, now-extinct, Ice Age megafauna of Australia.

The beast under the ‘microscope’ is Diprotodon optatum, famous for being the largest marsupial that ever existed. It stood 1.8 metres tall at the shoulder and weighed in at around 3,000 kg.

Diprotodon was one of the very first fossil animals ever described from Australia. Subsequent fossil records show that it had a near cosmopolitan distribution across Ice Age Oz, plus was one of the last surviving members of the megafauna.

But there’s a lot that we just don’t know about this animal, such as how it responded to seasonal changes; what its ecological role was; it’s basic biology… important questions that are critical in helping us understand why we don’t have Diprotodons anymore.

 

What we did

Our new study focussed on the life and times of an individual that once called the Darling Downs of southeast Queensland its home. We wanted to know what it ate, if it was a migratory species, and how it responded to changes in its environment.

Unlike some of their placental cousins, most modern marsupials don’t migrate at all. Some species, such as Red kangaroos (Macropus rufus) occasionally exhibit ‘nomadic’ migration where an individual or two will leave a home range, but with no specific plan or intention to return.

But what about Diprotodon? Weighing in at three tonnes, it’s more than 30 times the mass of the largest living marsupial, and likely had a very different ecological role when alive.

We applied a variety of geochemical analyses to a Diprotodon incisor tooth that we had borrowed from the Queensland Museum.

 

What we found

Without getting into the nitty gritty details, our study yielded some fascinating results. Firstly, our Diprotodon was clearly a seasonal migrant. It would undertake massive round-trips of up to 200 km per year as it tracked its preferred food source (basically, a combination of different species of grasses and leaves).

This is known as ‘two-way’ migration and is an evolutionary response to annually fluctuating resources.

 

Our discovery of such migration is a first for any marsupial living or extinct. That’s wildly fascinating in itself because marsupials have been around for a very long time. In fact, marsupials and their broader cousins, the metatherians (the group that includes all modern marsupials, but not placental or egg-laying mammals), have been on Earth for at least 160 million years. And until now, none have been known to have conducted such migration.

But perhaps more importantly, our data suggest that Ice Age Australia was just so ecologically different to anything that we’ve previously imagined.

In fact, the palaeo-ecosystem that we envisage seems more like the modern Serengeti than anything that we have Downunder today.

 

Some burning questions

At the end of the day, we’re left with even more questions than what we started out with. Which other megafaunal species migrated? What were the consequences of their removal from Ice Age ecosystems? And especially, what are the implications for understanding Australia’s modern ecology?

These are major questions that need to be addressed, and will form the focus of future investigations.

We are massively appreciative of all the institutions that supported this research: The University of Queensland, University of Rochester, Southern Cross University, and Griffith University. Huge thanks to the Queensland Museum (and especially Kristen Spring) for their support, Nathan Siddle for making the 3D model, and the Australian Research Council for funding this research.

There’s been a flurry of media reports out this year that have asked the question: Is the Tasmanian Tiger really extinct? Many of the stories are based off a media release put out by James Cook University where a couple of their researchers have plans to set-up a camera trap survey in north Queensland in search of this enigmatic marsupial.

Tasmanian Tigers, otherwise known as ‘Thylacines’ or ‘Marsupial wolves’, are thought to have suffered extinction on the 7^th of September, 1936. That might sound like a very specific date to know when anything went extinct, and it is. But there’s quite a tragic story behind it.

 

The demise of the Tasmanian Tiger

Most people will know that Tasmian Tigers were the top land-dwelling predator in Tasmania until British colonisation. A devastating combination of over-hunting, competition with feral dogs, and exposure to new foreign diseases, did not bode well for their survival.

In 1901, the Tasmanian Government recognised that they had a conservation problem on their hands… but did nothing serious to remedy the situation until it was too late.

It wasn’t until the 10^th of July, 1936, that legislation was finally passed that allowed for the protection of the Tasmanian Tiger. At that stage, Tasmanian Tigers hadn’t been reliably recorded in the wild for several years. In fact, the only known living member of the species at the time was Benjamin, a young adult male in Hobart’s Beaumaris Zoo.

Sadly, on one cold night in September 1936, a keeper forgot to let Benjamin back into his shelter and he was found deceased, exposure being the killer.

59 days.

59 days from the time that the Tasmanian Tiger was officially protected, to the time that the last known individual died.

 

But what if Tasmanian Tigers aren’t actually extinct?

Since 1936, there have been numerous but hitherto unverified reports of Tasmanian Tiger sightings. But is that about to change now that Science has become more involved?

It was interesting to read the plethora of comments that the public have left on the recent news articles and in social media. They vary from “hey, this is cool!” to “if they’re really out there, just let them be!”

As someone who researches, writes, and teaches science, I’m very much in the “this is cool” camp, but with a caveat. We can’t save what we don’t know about. I think that the key to conservation and environmental management is public awareness and education.

All that aside though, the recent media reports did get me thinking. What if Tasmanian Tigers aren’t really extinct? Could there be a viable population living in remote parts of north Queensland?

We know on the basis of the fossil record that Tasmanian Tigers did once live on the mainland. In fact, prior to around 4,000 years ago, Tasmanian Tigers also used to call New Guinea their home.

 

An unexpected discovery

My crew and I went on a fieldtrip a couple of years ago to some caves west of Townsville in north Queensland. Squirming around on my stomach in a tight squeeze of one particular cave, I stretched out my hand and picked up a bunch of loose teeth from the surface. It was an amazing moment for me and something that I’ll never forget: they were the teeth of a Tasmanian Tiger.

They were discoloured, so not quite the pearly whites that you’d expect with fresh teeth, but they were remarkably well-preserved. Both the crowns and roots were completely undamaged. That’s very unusual for any type of fossil, so you can imagine my surprise to find them like that.

Does this astonishing preservation and fact that they were found simply lying on the surface mean that they are actually really young?

I’ve not yet had an opportunity to fully analyse and date the teeth yet, but wouldn’t it be amazing if they were from an animal post-dating 1936. It would certainly challenge everything that we know about Tasmanian Tiger and their supposed time of extinction, not to mention also giving credence to anyone who has claimed to have seen a living Tasmanian Tiger on the mainland.

Better get to the lab…!

Huge land turtles, 8-foot tall kangaroos, massive cold-blooded killer goannas… these are but a few of the giant animals that once roamed Australia during the Quaternary: the period of geological time that we often refer to as the ‘Ice Ages’. But what happened to these megafauna? When did they go extinct and why?

It’s a research area that I am most fascinated by. And talking to others, it’s definitely something that inspires a lot of discussion and debate. I mean, who doesn’t love a good mystery, right? And in this case, it’s an Ice Age cold case and one of the biggest research questions in the Australian palaeo-sciences.

 

Extinction and public opinion

I recently had the privilege of being invited to give a presentation for BrisScience. BrisScience is a Brisbane-based monthly lecture series that aims to bring scientists and their science out of the lab and deliver it direct to the public. So for me, that meant packing up my thoughts and turning it into something digestible and interesting for a diverse audience.

It doesn’t matter if you’re a hardcore scientist or just a regular person walking down the street, everyone seems to have an idea about what happened to the megafauna. For scientists, they might form their opinion based on reading scientific literature. For members of the public, a lot of the time their thoughts might be crafted by things like media reports or easily assessable information websites such as Wikipedia.

Working in this space day in, day out, it’s sometimes hard to gauge an idea what people outside of the research community actually think. But here at BrisScience, I had an opportunity to go direct to the public and get their thoughts.

During the presentation, rather than have the audience put up their hands and shout things out, I used Mentimeter software to pose the question: “Why did the megafauna go extinct?” The audience were invited to go to a particular website and type in their answers using their phones. The answers were then broadcast live directly into my PowerPoint presentation as an evolving word cloud.

The results were really fascinating! There were 105 respondents out of the 300 or so in the room. Aside from a few creative answers such as unicorns, Jesus, and Flying Spaghetti Monsters, there seemed to be a clear candidate for the extinctions: climate change.

 

 

An unexpected response

Science tells us that the time of the megafauna was punctuated by repetitive wet and dry phases in climate, with a long-term trend towards progressively drier and drier conditions. In fact, the last glacial cycle that led into the most recent Ice Age was the harshest episode of climatic change of the entire Quaternary.

But I didn’t tell the audience that prior to the survey. All I had mentioned was that humans arrived in Australia around 55-60 thousand years ago, that the Quaternary was characterised by swings in climate, and that the megafauna were (mostly) extinct.

Climate change was not the answer that I was expecting; I thought it would have been human hunters for sure. But in a way, I found a lot of comfort in the overarching public view.

That’s not because I necessarily think that climate change wiped out all 90 species of Australian megafauna, but because of the worrying way that the debate has been playing out of late.

 

What we really know about the extinctions

There have been a spate of finger-pointing research articles recently, all arguing that human hunters solely drove the extinctions. Those research articles have translated into extensive and global media coverage as well, with headlines screaming out: ‘PEOPLE DID IT!’

I’ve read those research papers very closely and must say that I’m not convinced. Aside from some howling mistakes (like this one reporting the extinction of the kangaroo, Macropus, 43 thousand years ago… Macropus are very much alive and well, and include modern species like Red and Grey kangaroos, as well as 13 or so other extant members), the data just don’t stack-up to comprehensively ‘prove’ that humans did it.

Ideally, to test the human overkill model, you need to first show that as soon as humans arrived, all 90 species of megafauna immediately went extinct, and that climate change was not significant at the time.

A close reading of the actual datasets shows only around 15 species of megafauna date to the time period of human arrival. Most species significantly pre-date humans, or have no reliable dates at all. That is, we don’t even know when the majority of megafauna evolved, let alone, went extinct. As for climate change, a huge range of independent datasets demonstrate a big shift toward arid conditions right around the time of human arrival, so obviously, climate change cannot be excluded from the extinction equation.

The BrisScience survey was a great exercise in the end. The thing that pleased me the most, perhaps with the possible exception of whoever gave the answer “Flying Spaghetti Monster”(!), was seeing a public that are independent thinkers and are driven in seeking out the truth using alternative media.

To the BrisScience audience that night, thank you so much for coming and of course, thank you for your wonderful participation!

There’s an old joke in reference to the wildlife in Australia that “everything is trying to kill you”. While that might be a fun way to scare tourists, there is no joking about the murderous killer lizards of the last Ice Age. In fact, we have just uncovered the first fossils to show that those huge lizards were still stalking the bush when the indigenous people migrated from South-East Asia to the Australian continent.

Imagine being one of those first human inhabitants of Australia. It’s around 50,000 years ago, and you’ve just finished a most extraordinary sea journey from tropical South-East Asia. You’ve already said goodbye to your family and friends and are about to begin life in a foreign southern land where the climate, landscape, vegetation and animals are completely different. It’s a scary enough image as it is, but throw in the giant predators of the last Ice Age and that image becomes truly terrifying…

 

Read the full article in the April 2016 issue of the pop-science magazine, Australasian Science. This write-up is based off an earlier technical publication from my research team:

Price, Gilbert J., Louys, J., Cramb, J., Feng, Y.x., Zhao, J.x., Hocknull, S.A., Webb, G.E., Nguyen, A.D., Joannes-Boyau, R. 2015. Temporal overlap of humans and giant lizards (Varanidae; Squamata) in Pleistocene Australia. Quaternary Science Reviews 125(1): 98-105. Available here: http://www.sciencedirect.com/science/article/pii/S0277379115300809