Once you gathered together your pile of fossils, how do you know what you have? These students had a guide to what the bones and teeth of various animals looked like to help them.
And it’s also good to have a resident paleontologist nearby to help you identify things. These scientists have been studying bones and teeth of animals for over 30 years, so they know what they are talking about.
The students sorted their finds neatly into groups.
Some of them found some interesting things…
All this sorting helped the paleontologists catalogue what was in the pile, which told us the kinds of animals alive back then.
Looking at the white board at the end of the session, there were a lot of different finds that day.
It goes to show how diverse the fauna was back then – even more so that now, in a way.
That comes to the end of our walk through the Pleistocene age of one million years ago. I’ll be on a blog break for the next two weeks, and will be back with some Devonian fossils from around 400 million years ago!
It was interesting to see paleontologists (albeit students) in action. How do you extract the fossils from this?
When the mine was redug out in the 1990’s, it was already in dirt form, not in rock form. But how to sort the fossils from the dirt?
First you put a pile of ‘dirt’ in a sifter (the metal box).
Then you give it a good wash in the trough.
You lay out what’s left in the sun to dry.
And then collect it, ready for sorting.
Outside, we saw the cave where Mitchell and Rankin found the first diprotodon bones.
But as more bones were discovered, they found bones of creatues that were distinctly reptilian.
There were fossils from a giant lizard, which they named megalania. They were much bigger than present day Komodo dragons, at almost 5 metres in length. We saw a full-size replica in the bush.
But more interesting I think were the Wonambi – giant snakes. Here is a replica at the bottom of a sink hole.
These snakes were estimated at 10 to 11 metres long. We saw some vertebrae that had been collected.
Three vertabrae just fitted into a drawer, and if you think of how a human back bone looks in comparison to its size, then it’s obvious that this snake was very big.
Perhaps this was what the early Aboriginals saw when they first came to Australia? Perhaps this was their Rainbow Serpent?
In fact, there were lots of interesting marsupials around a million years ago, that are now extinct.
Later, we were shown lots of evidence of them. Here is an assortment of different kangaroo jaws.
Teeth from a giant wombat.
Even the front tooth from a palorchestes – a marsupial tapir – that we found on the ground.
Of course, the marsupials weren’t on their own. There were other interesting creatures around at the time too.
The diprotodon might have been big, but by most accounts it was a gentle giant. There were however carnivore marsupials around at the time too, and ones that were bigger than the Devils. The most ferocious was a species called thylacoleo – the marsupial lion.
We saw a replica of a full skeleton, and there were bits and pieces also on display. The animal is likened more to a leopard than a lion, in that it was of similar size, had a powerful jaw and teeth like sheers, and long retractable claws to slash its prey, and scarily, climb trees. It would be the most ferocious drop bear you’d ever see. They were so effective in their hunting that they would prey on the hapless diprotodon and other large herbivores.
Glad this guy isn’t around anymore!
Back on the surface, we were shown a few diprotodon fossils, which showed how big this marsupial was.
Its molar. Compare it with a human molar and you quickly get the picture.
Its thigh bone.
And a close up of a replica skull.
No wonder it was the biggest marsupial that ever lived!
I don’t think the early colonials knew what they were getting themselves into when they found the first big bones in Wellington Caves. This is a replica of one creature they found.
It’s the size of a hippo, but there wasn’t anything remotely as big in Australia these days. So what could it be?
They found a diprotodon. It’s a wombat-like herbivore, a marsupial, but one that was between the size of a hippo and an elephant. They were around one million years ago, when the area around Wellington Caves was much wetter, and there was much more vegetation to eat. They died out perhaps 25 to 50 thousand years ago, although scientists are still arguing why (climate change?).
Imagine having one of those roaming the back paddock.
Phosphate wasn’t the only thing the miners found.
The deeper they went, the more fossils they found.
At one place, there was a wall full of bones and teeth.
Over the years, paleontologists have been digging up and studying the fossils found in the mine. Some even ended up in Germany.
But how had the animals got there?
Scientists think it might be one of two ways. Remember the bats, the ones who produced all the poo? These bones might be the remnants of their kills. That’s why there were a lot of small animals there – rodents, snakes, bandicoots, and other small marsupials. The second way was that they fell into the caves through sink holes and couldn’t get back out.
The first explanation covers the shards on the walls. The second covers the bigger things they found. We’ll see what they were next.
In the mine, you could see cross-sections of the limestone. How the minerals and water crystalised and formed calcite.
But what was this phosphate they were digging out? The phosphate in this particular mine was formed from decomposed bat guano. That’s right, it’s very, very old bat poo from the Pleistocene (around 1 million years ago). You can see it here as the white bits.
And here seaping into the rock crevices.
We walked into the phosphate mine, and were transported to another world.
The mine was only operational during the first World War. Australia needed phosphate for both agriculture and to make explosives. However, the story goes the operators only started it to get government funding, as the mine had very little phosphate at all. When the war was over, they closed and backfilled the mine.
In the mine there are a few remnants of what it must have been like to work it in the bad old days. You could see that the mine was dug out by hand, from the pick marks on the walls.
The rails for the trolleys were still in place…
… As well as an old shovel.
All of this was buried until the mine was dug out and revamped in 1996 for the tourists.