More than 100 million years ago, a flying reptile called a pterosaur flew over the oceans hunting squid and fish.

Much more recently, one of its wing bones was discovered in Brazil, transformed over the aeons into a fossil made of a complex assemblage of different chemicals and minerals.

And in new research published in iScience, my colleagues and I found that the fossil bone still holds secrets of the creature’s life, including microscopic inner structures of its bones and molecular traces of its biology and diet.

A fossil treasure from Brazil

The fossil comes from the Romualdo Formation in the Araripe Basin of northeastern Brazil, one of the world’s most spectacular fossil deposits. The site has yielded exquisitely preserved fish, turtles, crocodile relatives, and pterosaurs.

Many fossils from the Romualdo Formation are preserved inside rounded rock nodules known as carbonate concretions. These mineral structures form shortly after burial, effectively sealing the remains from the environment. Think of them as natural time capsules.

Our fossil is a hollow wing bone, or phalanx. Pterosaur bones were thin and lightweight to aid flight, so they are rarely preserved in such detail.

Using high-resolution CT scanning, we examined the bone’s interior without breaking it open. The scans revealed layers of minerals with different densities filling the cavity – evidence of a complex sequence of chemical events that preserved the bone. We used several other methods to identify the minerals.

Microbes helped decay – and preservation

The fossil’s exceptional preservation may have begun with decay. As the pterosaur’s body decomposed on the ancient seafloor, microbes broke down tissues and altered sediment chemistry. These changes triggered the rapid formation of phosphate minerals.

One mineral in particular, called fluorapatite, formed within and around the bone, stabilising delicate features before they could be lost. Under the microscope, we could still see microscopic canals that once carried nutrients through living tissue.

Mineral analysis revealed evidence of microbial activity. We detected barite and celestite, minerals associated with sulphur-using bacteria. These microbes drove chemical reactions that helped create the conditions necessary for preservation.

In other words, ancient microbes didn’t just decay the body, they also helped preserve it for science.

A mineral vault for ancient molecules

After early phosphate minerals stabilised the bone, a sequence of calcite layers gradually formed inside and around it. These derived largely from carbon released during the decay of fatty tissue.

First, a thin layer of fine-grained calcite formed along the bone surface, followed by a second, slightly coarser-grained one. Over a longer period of time, larger calcite crystals formed, ultimately filling the bone cavity.

Analysis showed this calcite was low in an isotope called carbon-13, which indicates it partly came from organic carbon sources, such as fatty lipids and residual bone material. In contrast, any remaining organic matter in the bone appears to have relatively high levels of carbon-13.

The multi-layered mineral barrier acted like a geological vault, protecting delicate structures and organic compounds trapped in the bone from chemical degradation for millions of years. This protection allowed molecular traces such as steroid biomarkers and collagen fibre patterns to survive, giving us a rare window into the biology and diet of this ancient flying reptile.

Molecular traces of ancient life

Within this mineralised structure, we detected molecular traces of life called steranes, which are derived from steroidal lipids once present in living cells. To our knowledge, this is the first time steroid biomarkers have been reported from a pterosaur fossil.

Even more exciting, these molecules carry dietary clues. Carbon isotope analysis of cholesterol-derived compounds suggests this pterosaur likely fed on fish or squid-like marine animals, which is what we would expect from the shape of its teeth and skull.

The fossil also preserves microscopic structures resembling collagen fibres, the protein framework that strengthens bone. Although chemically altered over millions of years, the fibre patterns remain visible and resemble those seen in modern birds, which are distant relatives of pterosaurs.

Reading fossils in new ways

Discoveries like this one are transforming how we study fossils. Instead of examining only bone shapes, we can now recover chemical and molecular fingerprints as well.

Understanding how these exceptional fossils form may help identify other specimens capable of preserving ancient biomolecules. More broadly, our findings show that under the right conditions, molecular traces of life can survive for more than 100 million years.

Even after millions upon millions of years, ancient life can still leave behind chemical clues waiting to be discovered. As analytical techniques continue to advance and unusual modes of preservation become better understood, there is increasing potential to recover previously inaccessible information.

In the future, we may even be able to detect ancient DNA fragments or other molecular remnants in exceptionally preserved fossils, including those of dinosaurs and pterosaurs.

Kliti Grice, John Curtin Distinguished Professor of Organic and Isotope Geochemistry, Curtin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!

What exactly happens in the body when we sweat? – Bianca, age 9, Sydney

Hi Bianca, thank you for your question.

Sweat comes from special parts in our skin called glands. You might be able to see them if you have a very strong magnifying glass.

Try to find lines on your skin, and look where those lines meet. There you will find a sweat gland – we are born with about 2 million of them.

When we get hot, sensors in the body tell the brain. The brain then tells the sweat glands to work, and we sweat. That sweat is salty as it comes from the salty fluid found inside our bodies. We are 60-80% water. If that sweat can evaporate, we will cool down. This is why humans sweat.

Do you have a dog, Bianca? I bet you know what dogs do when they get hot; they pant. They take many small breaths and hang their tongues out. Gross! When they pant, water drops fall onto their fur. When those drops evaporate, they cool down. We often see cats licking their fur. Because dogs and cats do not sweat like humans, panting and fur licking helps them to stay cool. Cats always think they are cool.

All healthy humans sweat. We do this for two reasons: either because we are hot and need to cool down, or because we are stressed.

How does sweat cool us down?

Think about water, ice and steam. Did you know they are all just water?

Water looks different depending on its temperature. Ice is frozen or solid water. Steam is heated water that has turned into a gas called water vapour.

Try this experiment: lick the back of your hand and then gently blow air over the wet skin. What do you notice? It feels cool, right?

Blowing on your skin makes the water turn into water vapour. The word we use when this happens is “evaporation”. Evaporation helps take away heat.

Why else do we sweat?

So what about that other type of sweating I told you about?

Do you get nervous when you have to speak about something in front of your class at school?

In my job, I have to speak to other scientists at special meetings called conferences. I get nervous about that. Sometimes, I get so nervous that I get sweaty.

Some people get sweaty hands, some get sweaty under their arms and some just sweat all over. I am in the last group. We call this nervous sweating.

Sweating can also happen during an exam or when we are concentrating hard on something important. We don’t know much about this type of sweat, but we do know that it comes from the same sweat glands.

Thank you again for your question Bianca, and I hope my answer is helpful.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:

* Email your question to curiouskids@theconversation.edu.au
* Tell us on Twitter by tagging @ConversationEDU with the hashtag #curiouskids, or
* Tell us on Facebook

Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Nigel Taylor, Associate Professor of Thermal Physiology, University of Wollongong

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky! You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.

How do we smell? – Audrey, age 6, Brisbane.

Audrey, you have asked a question that humans have wondered about for centuries. And it’s only pretty recently we have started to really understand the answer.

Whenever we smell something, our nose and brain work together to make sense of hundreds of very tiny invisible particles, known as molecules or chemicals, that are floating in the air. If we sniff, more of these molecules can reach the roof of our nostrils and it is easier to smell a smell.

The fact that we have two nostrils allows our brain to detect small differences in the number of molecules that reach each one, so we can follow a smell trail just like tracker dogs. Have you ever tried finding where a smell is coming from? See how hard it gets with one nostril blocked.

The sense of smell also help us taste food. That is why food tastes bland whenever your nose is blocked.

Inside your nostrils, there are tiny things called neurons that “talk” to each other using electrical messages (our brains are mostly made of neurons too, by the way).

Smell memories

These type of tiny cells, called olfactory neurons (olfaction means smell), have long cable-like connections that send electrical messages to a spot at the front of the brain, known as the olfactory bulb. Each olfactory neuron connects with a different neuron in the olfactory bulb, which then sends this information to other areas of the brain.

The parts of the brain that get these signals also do other things, such as storing memories or provoking emotions. That is why some smells can bring back old memories.

Even some older adults can remember the smell of their kindy class, or their grandparent’s house. Also, some smells can make us feel scared or happy, such as the smells of smoke or flowers. For example, the smell of freshly mowed lawn can help us relax.

Do you have nice memories of a place or food that you have smelt in the past?

How animals smell

The sense of smell is very important to almost all animals, as it helps them find food, recognise family members, and avoid danger.

For example, the nostrils of fish and sharks let them smell underwater, even though they breathe water through their mouths and gills. Some animals, like dolphins and whales, have lost the sense of smell as, over millions of years, their nostrils have moved to the top of their heads and evolved into blowholes.

The way smells are felt by the nose and brain is very similar in all animals. Even the way olfactory neurons work is also very similar to that of insects (but insects smell using their antennae, not with nostrils).

The way the brain deals with smells is very different to how it deals with other senses, such as seeing and hearing. For example, we can identify the different instruments playing in a band, or the different shapes and colours in a painting. But it is very hard for us to tell the individual parts of a smell mixture.

We can feel the smell “orange” or “coffee” as a single thing, but have trouble identifying the many different parts that make up those smells individually. However, it is possible to get better at this with practice. Professional wine-tasters or perfume-makers can detect more parts of a smell mixture than most people.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:

* Email your question to curiouskids@theconversation.edu.au
* Tell us on Twitter

Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Rodrigo Suarez, ARC DECRA Research Fellow, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.

Why do we have tonsils????? – Ryan, age 10, Blacktown.

Thanks Ryan. I am guessing, based on the number of question marks you’ve used, that your tonsils might have caused you some trouble. You’re not alone.

The truth is that unless you are a baby, you don’t really need tonsils. Many people have them removed and live happily without them. I’ll tell you why, but first I have to explain what your tonsils actually are.

Waldeyer’s ring

The technical term for your tonsils is “palatine tonsils”, which means the tonsils of the palate. These lumpy things sit on either side at the back of our mouths. The palatine tonsils are one pair of a set of four tonsils that form a circle at the top of our throat.

At the back of our nose, we have the adenoids. They are another type of tonsil tissue, technically called the “nasopharyngeal tonsils”. There is also a blanket of tonsil tissue over the back of our tongue called the “lingual tonsils”, which we can’t normally see. The adenoids and the tonsils are linked by a thin strip of tonsil tissue on each side; these are called the “tubal tonsils”. Together this whole ring of tonsil tissue is called “Waldeyer’s ring”, named after a nineteenth century German anatomist.

Tonsils are important for immune defence

Waldeyer’s ring forms part of our immune system, along with our lymph glands (which are either side of your neck).

In early life, the lymph glands are not completely developed, and our bodies rely on our tonsils to trap bugs and foreign material that we either breathe in or swallow. By trapping these particles, the body begins to recognise them as potentially dangerous things and produces things called antibodies to kill them so they can’t harm us. Tonsil tissue is particularly good at trapping these particles as it has valleys and holes (called crypts) which increase its surface area.

Tonsil tissue is particularly important in the first six months of life. After this, our lymph glands take over most of the work and the tonsils are essentially out of a job.

Tonsil trouble

As we get older, food and germs can still land in the valleys and crypts. They can then cause infections to develop, which lead to a sore throat or tonsillitis. Some infections can also cause the tonsils to grow in size. Huge tonsils and adenoids can block the airway and cause snoring or swallowing and speech problems. As nutrition and immunisation has improved, kids get tonsillitis less and less these days. Usually, an ear nose and throat surgeon like me gets called in to intervene more for obstruction (blockage) than repeated infections.

Shrinking tonsils

If tonsils are a problem, an ear, nose and throat surgeon can remove them by doing an operation. If they are simply too large, they can be shrunk down using special instruments which remove the valleys and crypts. This leaves a thin bit of tonsil tissue behind.

Shrinking the tonsils down reduces the amount of pain kids get and also reduces the chances of bleeding after the operation. The downside is that, in rare cases, the bit we leave behind can get infected, or can regrow - although this is uncommon.

People sometimes worry that by removing the tonsils, we may be more likely to get infections. This is not actually the case. The lymph glands take over the role of protecting us.

If tonsils are too big or keep getting infected, they end up being more trouble than they’re worth.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:

* Email your question to curiouskids@theconversation.edu.au
* Tell us on Twitter

Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Simon Carney, Professor of Otolaryngology - Head & Neck Surgery, Flinders University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Curious Kids is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.

Where do rocks come from? - Claire, age 5, Perth, WA.

Wow, Claire, what a great question. Sitting in a university, I rarely get asked such brilliant questions. So, thank you.

As strange as it sounds, rocks are made from stardust; dust blasted out and made from exploding stars.

In fact, our corner of space has many rocks floating around in it. From really fine dust, to pebbles, boulders and house-sized rocks that can burn up in the night sky to make meteors or “shooting stars”.

The Moon and our local planets – Mars, Venus and Mercury – are just the largest rocks floating around our part of space. These are all made from space dust stuck together over billions of years.

The ‘light’ rocks are on the Earth’s surface

Planet Earth is a rock too, but so much has happened since it was formed from dust and small rocks that smashed and stuck together 4.543 billion years ago.

As the space dust hit each other to make the earth, it got super hot and melted. The Earth was, at that time, a spinning ball of red-hot lava flying through space.

In this melted lava planet, heavy bits of the earth sank and the light frothy bits gathered on the surface.

Have you ever looked closely at a glass of milky coffee at a cafe? The dark heavy coffee is at the bottom, whereas the light, frothy milk sits on the top. Well, our planet was a bit like that coffee billions of years ago.

We don’t see the really heavy rocks these days because they sank deep in the planet very early on. The rocks we see on the surface are like the frothy milk! They were light and rose to the top. Then, as time moved on, the planet cooled and froze to become the solid earth we have now.

I know most rocks are heavy. But in fact some rocks – even really big ones like Uluru – are actually much lighter than the rocks found in the deep Earth.

Lava and plates

Those rocks on the Earth’s surface actually move around. Large chunks the size of continents (called “plates”) jostle each other and this can cause earthquakes. Some of them get forced under other plates and heat up and eventually melt. This forms more lava. The lava erupts from volcanoes, then cools and forms new rocks.

Here are some pictures of lava in the melted state and then after it has cooled down:

Mountains and gems are also rocks

Mountains form where two plates smash into each other. The rocks that get caught between two of the Earth’s plates get squashed under huge pressures and heat up. These can form really beautiful rocks. Sometimes gems form in these rocks and people try to find them to make jewellery.

Rain and ice break up the rocks in mountains. These form sand and mud that get washed out to form beaches, rivers and swamps. This sand and mud can get buried, squashed and heated, which eventually turns them into rocks.

Rocks contain a record of the history of our planet; what is has been through and what is capable of. We are only just learning how to read it.

So, next time you see a rock, just think what an incredible story it contains.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au

Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.

Alan Collins, Professor of Geology, University of Adelaide

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Curious Kids is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.

How does electricity work? - Edie, age 5.

Electricity is all around us. Maybe some of the toys you play with run on batteries, which have electricity stored in them. You or your parents are reading this article on a computer, phone or tablet, all of which use electricity. The light bulbs, the television, the traffic lights, cars, aeroplanes – they all run on electricity. Electricity is exciting and important, so I am glad you asked this excellent question.

Everything is made from atoms

Everything is made from little tiny things called atoms. They are so small we cannot see them. They are much smaller than chickpeas, rice, ants, and ant eggs.

Because atoms are so small, we need a lot of them to make things. For example, a grain of rice has billions and billions and billions of atoms. Those atoms make up the rice, in the way LEGO pieces make up a LEGO car or house. They atoms click together and hold onto each other.

Even though an atom is extremely small, it is also made from even smaller things.

One of the things that make up the atom is called an “electron”. Electrons have many jobs. Some electrons help the atoms hold onto each other. Scientists call these electrons the “bonding electrons”. Bond means to stick together.

Other electrons just keep running around in the atoms. They are free electrons and they’re always on the move. Sometimes, they can move from one atom to another.

Electricity happens when electrons move from one atom to another.

Electricity in the power cable

So, the story so far: we know there are billions and billions and billions of atoms. There are also billions and billions and billions of electrons in everything around you. A leaf, a plastic cup, your pet - they all have electrons. Some things, like metals, have more free electrons than other things. A plastic cup, for example, doesn’t have as many free electrons.

You probably have a lot of power cables at home. They might be plugged into the TV or computer or a phone charger. Power cables have a huge number of free electrons.

When the free electrons in a power cable move from one atom to another, almost all in the same direction, you get something called an “electric current” running through the power cable.

How do we push the electrons through the cable? Adults do that by plugging the cable into a wall socket.

Remember, electricity can be very dangerous and can even kill people, so it’s important that kids just let adults handle the cables and wall sockets.

The socket makes a thing called “voltage”, which is like an invisible force that pushes all the electrons in the same direction down the cable.

Once the cable is plugged into the socket, the socket pushes the electrons inside the cable, like cars moving down lots of lanes in a highway. The electrons inside the cable then keep pushing each other forward (and sometimes back and forth depending on the type of electricity). This creates an electric current inside the cable.

The cables have a kind of jacket (which we call “insulation”) on the outside to keep the electrons moving along the metal safely. These jackets make it safe for us to use electricity by keeping them in the metal.

But where does electricity come from?

Electricity comes from power stations - great, big places that can make electricity in different ways.

One way is by burning coal. But this way is bad for our environment. Some power stations use the light from the Sun to make electricity, using large solar panels. Or they might use wind, or water to make electricity. These methods are not as bad for our environment.

If you’re interested in learning more about how electricity is made, check out this Curious Kids article over here.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.

Sherif A. Tawfik Abbas, Research Fellow, RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.