How to Identify Common Fossils

How to Identify Common FossilsFossils are the remains of ancient life that has been buried for thousands to hundreds of millions of years. There are plenty more fossils than the ones displayed in museums, and many can be found by amateur fossil hunters. Common fossils will vary depending on your location and can be found in many different forms.


Difficulty: Moderately Challenging

Things You’ll Need:
  • Guidebook with Geologic Index Maps
Step 1
Look for fossils near rocks that are likely to be fossil-bearing. According to The National Audubon Society Field Guide to North American Fossils, most fossils are discovered in rock formed by sand, silt or fine sedimentary rock that may have hardened under water at one time. Shale, sandstone and limestone are the main examples.
Step 2
Keep an eye out for plant fossils. These are quite common in many areas in North America; however, they can be quite hard to identify because oftentimes the imprint of a leaf, stem, seed or flower is not whole. If you find a plant fossil, cross-reference it to a fossil guidebook with color photos and concentrates on North America or, if possible, the state in which you found it.
Step 3
Consult the geologic index maps in your guidebook to see how old the rock is in the area in which you found the fossil. By knowing the age of the rock, you may rule out certain species or have a better idea of what you are looking at.
Step 4
Use the rock around the fossil to give you more information. For example, sometimes the hard parts of a fossil like a shell or bone may have dissolved but left a hollow space in the rock where it used to be; these are called molds. From looking at the shape, size and any imprints on the surrounding rocks, you may be able to better determine what it used to be.
Step 5
Search for trace fossils as well as typical fossils. These could be footprints or feces (coprolites), which may contain hints of what the animal ate during that time period.
Step 6
Think outside of the box. Petrified wood, bone and amber are all types of fossils called petrifications. Always use as many clues as possible to help identify what it is you have actually found. If you have found a piece of petrified wood, for example, are growth rings visible and, if so, how many? What texture is the bark if intact?
Step 7
Cross-reference as much as you can. There are plenty of shells, gastropods, arthropods, sponges and other fossils from the sea that can be identified rather adequately with a guidebook, but not everything can be identified by simple visual observation. Sometimes having it analyzed by a professional is the best action to take.

Article Written By Naomi Judd

Naomi M. Judd is a naturalist, artist and writer. Her work has been published in various literary journals, newspapers and websites. Judd holds a self-designed Bachelor of Arts in adventure writing from Plymouth State University and is earning a Master of Fine Arts in creative writing from the University of Southern Maine.

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