• Stacia Martineau

DIY Dinosaur Fossil Dig!

Every summer, dozens of people visit the Dinosaur Center just to show us the things they have found. We’ve seen hadrosaur legs, tyrannosaur tails, giant ammonites, strange rocks, and even fossil poop! Some of the best discoveries in paleontology in the last 150 years have been found by regular people! This has brought up a couple questions.


  1. What should I do when I find a fossil?

  2. And, if absolutely necessary, how do I safely remove it from the ground?


We here at the Dinosaur Center want to help you answer these questions.


Tools and Equipment


Before you start looking for fossils, make sure to have the proper equipment so that you can thoroughly document and safely remove any fossils you might find.

While exploring for fossils, it’s important to take with you:

  • A map

  • A compass

  • A radio (or cellphone)

  • A camera

  • A GPS (optional)

  • Sunscreen

  • Snacks!

  • Water!

  • And a first aid kit.


If you find a fossil and want to remove it, make sure you have:


  • A rock hammer

  • An awl (or screwdriver)

  • Plaster bandages (optional)

  • Work gloves

  • Aluminum foil

  • Duct tape

  • A multi-tool knife

  • Toilet paper

  • Plastic bags

  • A magnifying glass (or hand lens)

  • A scale bar (or ruler)

  • Consolidant (glue)

  • A notebook (optional)

  • And something to write with


Other helpful tools might include chisels, abrasive saws, jack hammers, dynamite, rock drills, pneumatic tools, back hoes, excavators and – when you’re really in a pinch – tweezers.

Want more detail? Check out what’s inside the backpack of Carrie Levitt-Bussian, the Paleontology Collections Manager at the Natural History Museum of Utah.


What Do Fossils Look Like?


At the Dinosaur Center, we’ve got a fancy little trick to help you remember what to look for when identifying fossils. We call it “The 4 S’s” (thanks Maeve!).

  • Shape: Fossilized bones tend to have sharper corners and straighter edges than their rocky counterparts. They’ve spent less time on the surface getting moved around than their rocky counterparts, and so they haven’t been rounded and smoothed over yet.

  • Shade: During the process of fossilization the bone is slowly replaced with minerals that are dissolved in the local groundwater. These minerals can affect what color a bone ultimately becomes. Along the Rocky Mountain Front - where we work - the fossilized bones contain a lot of iron and so our bones are typically shades of orangey-brown. Further south there is a lot of manganese in the bones, which causes them to turn black.

  • Striations: All bone, whether modern or fossilized, has a distinctive striped pattern created by tiny tubes that run through the interior. Seeing these lines and pores is a great way to tell whether something is a bone or not. Look out for these look-alikes: petrified wood, limestone, quartzite.

  • Stickiness: Also known as the “Lick Test.” If you lick your finger and then stick a suspected bone on it the bone will stick, but rocks will not. Dinosaur Center field instructor, Erin, holds the record for longest time stuck to a bone: 2 hours, 37 minutes!


Write it Down


In the immortal words of Adam Savage, "the only difference between screwing around and science is writing it down." The contextual data for a fossil is almost as valuable as the fossil itself. This kind of data includes pictures, maps, sketches, written descriptions, and a record of tools and glues used on the fossil.


So when you find a fossil, the first thing you should do is take lots and LOTS of pictures of the fossil from many different angles before you move it. At the Dinosaur Center, we take two types of photos: close-ups and landscapes.


Close-Up Pictures

These photos are used to identify the fossil and the type of rock it is buried in. We take close-up photos from a distance of 10 centimeters to 1 meter away from the fossil.

Close-up photo of dinosaur rib

Things you need in a close-up photo:


  • A scale – most often this is an object like a ruler, but any object with a fixed size will do (ex. hammer, water bottle, pen, etc.)

  • Clear focus – blurry photos don’t do anyone any good. Check your pictures before you collect or move on.

  • Multiple angles – many bones look the same from one angle, but totally different from another. Taking pictures from different directions can help scientists identify the specific bone you have, and maybe even the type of animal!

  • Low contrast – either keep all shadows out of the photo (if possible) or arrange yourself so that the whole photo is in shadow. It’s really hard to see fossils when half of it is washed out or too dark.


Landscape Pictures

These photos are used to identify the location of a fossil. In the past, landscape photographs have helped paleontologists find historic sites that have been abandoned for nearly 100 years!

Landscape photo showing site location

Things you need in a landscape photo:


  • Landmarks – something that won’t go away anytime soon (ex. bends in a coulee, rock layers, mountains, a large rock, a tree, etc.)

  • Time and Date – the landscape can look very different depending on the time of day and the season, we highly recommend making a note of these somewhere.

Mark It on a Map

If possible, you should mark the fossil’s location on a map or GPS unit. While it’s possible to find sites based on pictures, you can save a lot of time later by marking your coordinates. Need a map? The USGS has lots of maps available, both for sale and free download. Also, make sure to note which coordinate system you are using; here at the Dinosaur Center we use either UTM Zone 12 or WGS 84.


Write Down Observations

Do you remember everything you did yesterday? How about a year ago? Neither do we. It’s hard to keep track of all the different fossils one might see in one day of looking for fossils, so writing notes in a journal is a good idea.


Here are some ideas for observations to write in your own journal!

Removing Fossils


[Note: Before removing any fossils from the ground, please make sure that you have obtained the proper permits and permissions from the landowner.]


Removing a fossil from the ground is tricky business – remember, that bone hasn’t been moved in millions of years! There’s more than one way to remove a cat – I mean, bone! But they all start the same way: consolidate, consolidate, consolidate.


Consolidation

Consolidation is the act of imbuing a fossil with thin glue so that it holds up better to transport and actually stays together. There are lots of different glues for this step, and every paleontologist has their favorite. At the Dinosaur Center we use Paraloid B-72, but other professional favorites are Butvar and Vinac. You can get these online (we recommend Talas), but in a pinch you can also use watered-down school glue (like Elmer’s). Be sure to write down whatever type of glue you use and don’t forget to let the glue dry!


Once the fossil is consolidated, it’s important to examine it thoroughly. Ask yourself…


  • Does the fossil go underground?

  • Are there any cracks?

  • How big is the fossil?

  • Does it break when I touch it?

  • What shape is the bone?

  • What kind of rock is it in?

  • Are there plants around it?


All of these questions will help you determine what method(s) is the best to remove your bone.


Plants

If there are plants around the bone, cut them away, don’t rip the roots out. Plants LOVE porous bones and their roots will often wrap around and inside the fossil. Ripping the plant roots can result in a broken bone.

Plant roots wrapped around fossilized bones

Rock (Matrix)

If the fossil is in hard rock, you may have to take the whole rock with you, and if it is in soft rock (like mudstone) then there might be more cracks than you can see on the surface. In general, the softer the rock, the more delicate the fossil. Last summer the Dinosaur Center crew worked on a dinosaur in extremely soft rock and the bones required a lot of glue to stay together.

A fossilized bison skeleton in soft mudstone
A turtle shell encased in hard sandstone caprock

Shape

If a bone is sturdy and compact (like a tail bone), you can probably get away with less support during removal than a bone with a bit that sticks out (like a dorsal vertebra). Thin bones, like those in the pelvis, will also require more support.

A sturdy tyrannosaur tail bone
A delicate hadrosaur vertebra with dorsal spine

Size

In the excitement of discovery it’s easy to forget that you need to be able to carry that fossil back to wherever you’re going. Here’s a handy chart to help you visualize how much fossils actually weigh.

Condition

Fossils almost never come out of the ground looking like the ones in Jurassic Park. The end goal for any fossil removed from the field is for it to be put back together, and that is sometimes easier said than done depending on its condition in the field.


  • Solid: This fossil has no cracks and no parts are at risk of breaking off if the fossil is shifted.

  • Cracked: The fossil is broken into multiple pieces, but the pieces can be easily fit back together.

  • Splintered: The fossil is broken into multiple pieces, but the pieces are either small enough or in a large enough quantity that they cannot be easily fit back together.

  • Powdered: There are no discernible pieces that can be fit back together. The bone literally disintegrates if you look at it wrong.

A badly splintered hadrosaur rib

Removal Materials

All of the above factors will help you determine what kind of materials you need to use when removing your fossil. Check out the graph below for a rough guide on when you should use different materials.

If your bone requires plaster and burlap, it’s best to get the professionals involved. Fortunately, most fossils found on the surface are in the small to medium range.

Hadrosaur femur that needs a plaster jacket

You might have noticed that not all small fossils can be thrown in a bag. This is because small, delicate fossils (like teeth, jaws, and hollow bones) can be damaged by rubbing against one another. Protect them with a layer or two of toilet paper before storing them in a bag. You can also use hard pill containers or film canisters for further protection.

Small mammal jaw wrapped in toilet paper

For larger, more solid bones that won’t fit in a bag, you can protect them by wrapping them in toilet paper and then aluminum foil. If the aluminum foil won’t stay tight, seal it with a few strips of duct tape.


Plaster bandages were (and sometimes still are) used to create casts for broken human bones in the field. They are essentially strips of cheese cloth that have been infused with dry, uncured plaster. Just add water and you’re good to go! They’re much easier to carry around than a bag of plaster and burlap sacks. We use plaster bandages to stabilize fossils out in the field so that the fossils are safe while we get larger quantities of plaster and burlap.


What Should I Do With My Fossil?


Donate it to a Museum

Some of the greatest dinosaur discoveries of all time were found by regular people! You can continue this great tradition by bringing fossils you find into your local natural history museum.


When you bring a fossil (or a picture of a fossil) to the Dinosaur Center, our paleontologists will examine it with all the other information you collected. Every new fossil is an exciting event that draws even the most introverted intern out into the open, so bring your own questions, too!


We will provide you with a donation receipt if you decide to leave your fossil at the museum. We may also ask to see the original site if there is enough evidence to suggest there are more fossils in the ground. Please note, however, that we will only pursue this line if you and the landowner are willing. For more information about how the Two Medicine Dinosaur Center works with our current and prospective landowners, check out this article written by our local paper, the Choteau Acantha.


Donate it to Your Local School

Inspire the next generation to love dinosaurs just as much as you do! We like to think of paleontology as a gateway science. Fossils are a great way for kids to engage and get hands-on with the past.


Keep it at Home

Here are some cleaning and preservation tips if you decide to keep your fossil at home.


  • Clean mud and dirt off the fossil gently with a toothbrush and water.

  • For harder rock, use a pin vise or small flathead screwdriver to chip the rock from the bone.

  • Keep your fossil in a dust-free area.


The Association for Materials and Methods in Paleontology has some great videos on preparation techniques if you want to get into the nitty-gritty of it!


Where Can I Learn More?


Join us in the field and ask us all your questions in person. Book your dig program for just one day, or for an entire week! This summer we will be continuing work on our hadrosaur in the Judith River Formation, in addition to our shorter, local programs.


If you’ve got a future paleontologist in your family I highly recommend Digging Up Dinosaurs by paleontologist Jack Horner. It’s one of my favorite books about field paleontology and it offers a really in-depth look at the excavation process.


Fellow Montana Dinosaur Trail museum, Museum of the Rockies, has written up a very thorough description of the process of finding, excavating, cleaning, and displaying fossils.

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