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Are Dinosaur Fossils Radioactive? What We Know About It 

You’ve heard many rumors about dinosaur fossils, but the one that caught your attention is that the bones might be radioactive. Is it true? Are dinosaur fossils really radioactive?


Are Dinosaur Fossils Radioactive?

In some instances, dinosaur fossils are radioactive. Where the fossils come from plays a big role in their radioactivity. Even if some fossils are radioactive, it’s not to such a degree where exposure should be dangerous for your health.

Dinosaur fossils, undisturbed remnants of the Earth’s prehistoric epochs, draw exciting links to radioactivity, an emitted energy from specific decaying materials. Paleontology, the discipline studying life’s history, hinges heavily on radioactive elements – particularly Uranium and Potassium-40 – to determine the age of these ancient fossils, allowing a glimpse into prehistoric time frames.

However, a central player in this arena is Carbon-14, a radioactive isotope crucial in setting the age of younger fossils. Meanwhile, the earth’s crust tends to be a significant reservoir of radioactive substances, thereby bridging geology and atomic nuclei in the intricate study of radioactivity.

Tucked away within the layers of the Earth, dinosaur fossils integrate isotopes of Uranium and Potassium-40 as they undergo radioactive decay over millions of years. Isotopes, characterized by their varying number of neutrons, have a significant bearing on what happens during the fossilization process, where organic materials metamorphose into minerals, sometimes infused with a dash of radioactive elements.

This leads us to half-life, a period registering the necessary time for half the radioactive atoms in a sample to decay, an essential element in the toolbox of aging techniques like radiometric dating. Furthermore, ionizing radiation – an energy emanation from unstable atomic nuclei – minutely influences the constitution and structure of dinosaur fossils.

Thus, the somewhat muted radioactivity coursing through these fossils provides a portal into the Earth’s past, enabling the unveiling of mysteries associated with these extinct giants. They enhance our understanding of the planet’s evolution, enthralling us with intimate glimpses into the timeline of dinosaurs.

We’re sure you have plenty more questions about fossil radioactivity, and we’re here to share what we know. Keep reading to discover whether you can safely touch dinosaur fossils and why some fossils are coated in lead paint. 

Are Dinosaur Bones Really Radioactive? More Details about Radioactivity

Radiation 101

Before we get into dinosaur bone radioactivity, let’s present a brief overview of radiation. 

Radiation is a source of energy with magnetic and electric fields that can move at the speed of light. On the electromagnetic spectrum, radiation is quite high. Gamma rays, for instance, are a form of radiation that can ionize atoms and eliminate electrons, so they’re powerful. 

It is what causes an atom to be radioactive. Ionizing radiation can affect a living creature’s DNA as well. Repairing the DNA can occur depending on the extent of the damage. In more severe cases, the DNA cell can turn cancerous or die.

Dinosaur Bones – Radioactive or Not?

Are dinosaur fossils really a source of radiation? As we touched on in the intro, the answer is yes. However, not all dinosaur bones are radioactive. Where the fossils are sourced determines the radioactivity of the bones.

For example, a 2020 article from Live Science detailed the findings of fossils in Utah. The Allosaurus specimen the paleontologists recovered was about 155 million years old. Although the paleontologists were able to find the Allosaurus’ body, they struggled with locating its head.

That is until they did a radiation detection test. Then the skull was uncovered. It was proven to be radioactive.

Here’s a way older example from the journal Nature that was published in 1967. In the early 1960s, paleontologists visited the Gobi Desert for several years. During their time there, the paleontologists found Upper Cretaceous creatures. The Mongolian fossils were, as the journal puts it, “highly radioactive.” 

For the fossils that have been proven to be radioactive, why is it so? There’s a simple explanation. 

Dinosaur fossils are always unearthed from the ground. In rock formations and soil, radioactive elements can exist. These radioactive elements likely didn’t kill dinosaurs, as they probably weren’t there when the dinosaur lived or even potentially when it died.

Through time, erosion, and other sediment changes, the radioactive elements got to the bones, where they then leached. It is what caused the radioactivity in dinosaur fossils. 

Can You Touch Dinosaur Fossils? Are They Dangerous?

Knowing what you do about radioactivity and its effect on humans and the fact that some dinosaur fossils are radioactive, you’re concerned. If you visit a museum with real dinosaur fossils that you’re allowed to touch, is your health in danger?

No, and for several reasons. 

For one, museums are a business (at least, most of the time), and businesses generally do not put their customers in harm’s way. An exhibit wouldn’t feature radioactive dinosaur bones because the fossils would be dangerous to staff as well as museum visitors. (Source)

We’ll talk more about this a little later in the article, so you’ll certainly want to see that. 

Okay, but about uranium radiation? After all, uranium exposure can cause liver, bone, and lung cancers. 

We couldn’t find any records of uranium-containing dinosaur fossils. Paleontologists use uranium-235 and uranium-238 to date fossils, but the fossils themselves do not appear to contain the chemical element.

Let’s say that you went to a museum that threw caution to the wind and knowingly displayed radioactive dinosaur bones. You touched said bones during your time at the museum. You’d still be okay. 

A 2018 article from the Houston Museum of Natural Science states that “some dinosaurs can actually be radioactive; not enough to harm you, but enough to be picked up by a Geiger counter.”

News site The Conversation in 2013 detailed how much radiation is safe for human life. The average amount of radiation people are exposed to annually is two millisieverts or mSv. The International Commission on Radiological Protection or ICRP states that up to 20 mSv a year could be hazardous to human health, and up to 100 mSv in five years could also pose health risks. 

While we don’t know how much radiation dinosaur fossils hold, it likely wouldn’t be close to 20 mSv, unless in the case of the highly radioactive bones we talked about before. (Source)

Besides, radiation is being introduced into your life in other ways if it’s not coming from fossils. Seriously, radiation is all around you every single day. Anytime you get a CT scan, that device uses radiation. The same is true of receiving X-rays.

You’re impacted by cosmic radiation if you live at sea level, likely without even knowing it. Cosmic radiation is also a factor for residents of Denver, Colorado, due to the high elevation there. 

A Denver resident would accumulate 0.8 mSv of radiation per year, which is not much at all. A head CT scan produces only two mSv of radiation. 

It is all to reiterate that you don’t have to worry about touching dinosaur fossils. Enjoy the privilege!  

Why Are Some Dinosaur Bones Covered in Heavily Leaded Paint?

Although you’ve never personally seen it, you’ve heard that sometimes dinosaur fossils are coated in lead paint. Lead is added to paint to prevent corrosion-causing moisture and help the painted surface look longer. 

Why would it be used on dinosaur bones? When museums come into possession of fossils that are likely radioactive, they apply lead paint to tamp down the radioactivity of the bones. 

Lead has many stable isotopes and is quite dense, making it an effective combatant against x-ray and gamma radiation. 

The risk of radiation exposure isn’t as much when handling the bones, but rather when cutting into them using instruments such as diamond saws. The dust that’s released would be dangerous to inhale. 

That lead paint can preserve the appearance of dinosaur fossils is an added bonus, but it’s not the primary reason it’s used. 

Other Dinosaur Fossil Preservation Methods

While we’re talking about fossil preservation, we thought we’d delve into the various methods that paleontologists and other experts use to maintain dinosaur fossils over the many generations so kids and adults alike can appreciate and learn from them. It’s truly fascinating stuff!

Preserving fossils is known as taphonomy and branches from paleontology. The two methods that paleontologists use to preserve fossils are altered and unaltered hard parts.

Altering a fossil’s hard parts takes place if some or most of its skeleton has dissolved, carbonized, recrystallized, or permineralized. We have to explain some of those terms.

Permineralization is a process in which pore spaces in a dinosaur’s bones receive a flush of minerals after groundwater travels through. The minerals harden, which is known as crystalizing, and the bones are preserved.

Recrystallization is when the bone or shell’s minerals become a new type of mineral. The chemical compounds don’t change, though. 

For example, a fossilized shell might begin as aragonite and become calcite, stabler than aragonite. Recrystallization can erase some small details of the original fossil, but its shape remains.

Unaltered hard parts are those in which their biological parts are unchanged. For instance, a dinosaur’s teeth would retain their composition in fossil records just as they did in the dinosaur’s head. That’s true of our teeth as well. 

Other unaltered hard parts are opal, aragonite, calcite, and apatite (no, not the same as appetite). 


In the millions of years that dinosaur fossils have remained buried in the earth, some are exposed to radioactivity through shifting soils. It’s that very radioactivity that has allowed paleontologists to find dinosaur species or fossil records that would have otherwise remained undiscovered without radiation testing.

Dinosaur bones that could pose a human health danger due to their elevated radiation levels are usually coated with lead paint. The fossils you see at your local museum don’t contain enough radiation to hurt you, so you’re free to touch if you’re allowed! 

There’s still lots more we hope to learn about dinosaur fossil radiation, such as whether the Cretaceous-Paleogenic extinction event produced the radiation we’re now finding in dinosaur fossils. For now, the information we have is quite interesting!