Paleontology/Field Techniques

Paleontology involves outdoor and indoor activities.

Finding, removing, and packaging fossils for transport are the major component of fieldwork done by paleontologists. The field work, however begins with preparatory work in the office or laboratory.

Finding a Location

Finding locations where you might find fossils begins by relying on previously recorded data. It may begin with conversations with or field notes from other paleontologists or geologists. This information can help you find places where fossils have previously been found. If you don't have access to unpublished field notes, or people who have worked in the area you want to dig, you can work with a geological map.

A geological map is a map covering the kind of rock or other material that underlies the landscape. A paleontologist wants to find places with sediment or sedimentary rock of the age the fossils you are interested could be located, and formed in the environment (freshwater, marine, or land sediments) where the organisms you're interested in might have been found.

In the U.S.A., State and Federal geological agencies (e.g. the United States Geological Survey) produce these maps. There are similar bodies in many countries, and international organizations that cover the geology of most of the world.

Is Your Location Accessible?

Before you head to a promising site, you should find out if it is accessible. Is the location covered by forest? Is it covered by houses? Consultation of a map or online mapping service can help you with this (see external links).

You also need to know whether or not you can dig there. You need to find out the ownership of the land. In almost every location around the world, all land is owned by someone - whether an individual, company, or government. Whether you can dig for fossils there depends on the ownership and the laws governing fossil digging.

For instance, in the U.S.A., property owners legally control all activity on their land, including digging for fossils. Trespassing, going on to private land without permission, is a crime. State and Federal entities that own land have varying rules about whether fossil collecting is permitted.

Whenever you plan on going fossil hunting, you should work to get permission from the owner in writing, along with any restrictions (e.g. "put any soil back where it was" or "pack out your trash"). On State or Federal land you may need a permit, which acts as your permission to dig, and lays out the rules for collecting.

Finding Fossils on Location

Students searching for fossils.

Not all fossils found are under sediment, in fact most of them aren't. Most are broken or chipped material that have weathered and eroded out of the surrounding sediment or rock. It makes little sense to move to a location and simply start digging in a random spot. Some rare finds may be made by randomly digging in a backyard, but these are few and far between.

Most fossils are initially found by simply walking around an area and seeing what's there to be seen. Places that are fruitful to look initially include the bases of any hill or cliff sides where material may have weathered out and fallen to the bottom. If you find something there, you can follow up by looking above where you find the fossil for others that have not yet been fully released from their resting place.

Excavating Fossils

Once you find a potential location, by having found weathered out fossils, you will need to excavate any fossils that are still in the rock, only very rarely would you be able to remove fossils by hand, so you'll need tools to do that.

Depending on the size and difficulty of removing the fossils from their matrix (the rock or soil it's in), the tools you may need may be large or small. They may include shovels or even jackhammers to remove the rock surrounding the fossil. Smaller jobs may only require rock hammers or small drills. For working close to the fossil and final field preparation, brushes and dental picks may be used.

The idea in the field is to get the fossil out as completely as possible, so generally a fair amount of the surrounding rock is included in the material taken back to the laboratory.

Field Preparation

Sometimes crumbling fossils need to be glued together in order not to break the fossil. Either as excavation progresses, or some time before transport, a fossil may need to be held together. Sometimes a reversible glue is used (see below for link).

The next step is to cover the excavated parts of the fossil with wet paper towels (or toilet paper, which is preferred by many paleontologists) over the specimen and it's surrounding rock. This protects the fossil specimen from the next covering layers.

Those covering layers consist of plaster coated burlap strips. If you have access to plaster impregnated bandages, usually used for making casts for broken bones, these are an excellent alternative. The plaster dries into a hard shell or jacket that protects the fossil during transport and storage until it can be worked on in the laboratory.

With some fossils, wrapping may be started before excavation is complete to protect the specimen. With others this is not necessary.

The final step is to label the jacket with the date, time, and specimen number. It is then ready to be transported back to the lab. With large fossils, the resulting package may be very heavy and may require a truck or helicopter if it is really heavy. Before beginning any excavation, you should make sure you have the means to protect and transport it from the field. Otherwise it should be left where it is for future excavation by you or someone else.

Field Notes

Field notes can be useful for recording geologic details.

Field notes are an essential part of paleontology field work. Usually notes are recorded on site, at the time events are happening. Your memory should not be relied upon. Most professionals record their notes in a bound volume so pages can't easily been lost.

Essential notes include date, name/s of the people involved, location, and what you see. You should include anything you find relevant or interesting.

Useful notes include things like a general description of the location is important (is it hilly? flat? is the rock exposed or under soil?). Specific notes about any specimens you find should also be included. Did you find it at the bottom of a cliff? What color is it? Add a short description or sketch of any fossil you find.

If you take photographs, make notes on how to find those photographs. You might, for instance, take an additional picture of you field notebook at a specific location before you move to another, so you can figure out which in a series of similar looking pictures are the ones you're talking about.

Field Numbers

Each specimen you find should be given a separate field number. Each person has their own numbering system. Whatever numbering you use, continue it from one fossil location to another. If you start your first fossil find with "1", your next fossil location should not restart the numbers at "1", but continue on, so that each and every fossil you find is given a unique field number.

In your field notes, record the field number alongside information about any specimen you collect, so you can refer back and forth, and can eventually label your specimen in the lab with the information about where you found it and other information from your field notes.

Back in the Laboratory

All the information you gather and care you take in the field is immensely valuable once you return to the laboratory to prepare your fossil for study and/or display.

External Links

• United States Geological Survey
• Google Maps, an online mapping service that can help find out whether an area has exposed rock.
• Adhesives and Consolidants from the American Museum of Natural History
• Field Techniques from the American Museum of Natural History