red fern fossil
Plant compression fossil



Fossils are the remains of once-living animals. Fossils can provide evidence for the appearance, behavior, physiology, and ecology of groups of organisms that have been extinct for millions of years. Combined with the data provided by the surrounding rocks, fossils tell the stories of ancient ecosystems.

Petrified Forest has plant and animal fossils from the Triassic Period, going back over 200 million years. The Triassic Period is sometimes referred to as the "Dawn of the Dinosaurs" because it is the time before the Jurassic Period when dinosaurs ruled the earth.

Find a thorough examination of the Triassic on our Paleontology page.
Learn specific information about our namesake fossil on the petrified wood page.

hands hold fossil pieces above trays with more fossil pieces
A paleontologist must look for a match among many scattered pieces

NPS/VIP Susan McElhinney

Pieces of the Puzzle

Fossils can be large or small; some petrified logs found in the park measure over 190 feet, whereas a single tooth may be a few millimeters long but contain the definitive characteristic of a new species.

Every fossil is like a piece in a three-dimensional jigsaw puzzle. Imagine putting together a jigsaw puzzle without knowing what the completed puzzle will look like. That would be hard, but what if you also didn't have all the pieces? Paleontologists are fossil puzzle experts and are able to predict and look for missing pieces.

Context is very important when finding fossils. Where a fossil is found, what else it is found with, how old the fossil is, and how it was preserved are clues just as important as the fossil itself. Every fossil found in the park is important because of its context; the context helps tell its story. If you find an interesting fossil, take a photograph of it, mark its spot on a map, leave it where you found it, and tell a ranger. We love learning new things with the help of our visitors!

researcher looks into microscope in room full of fossils
Prep lab at Petrified Forest

NPS/VIP Susan McElhinney

Paleontologists at Petrified Forest are able to take part in every step of the research process and are actively taking park in the scientific mission of the park. The hundreds of thousands of acres throughout the park are packed with fossils, and paleontologists research them year-round. Petrified Forest paleontologists are able to look for, collect, and bring back fossils from all over the park. After a fossil has been collected, it spends time in the preparation lab. Our lab allows scientists to remove rock from fossil bone using the perfect tools for the job, to mold and cast fossils for museum exhibits and public outreach, and to get fossils ready for publication. Petrified Forest also has on-site natural and cultural history collections, which house modern animal samples, fossils, and archaeological artifacts. Researchers come from all over the world to work in the park, from the field to the lab to the collections.

Check out the Science & Research going on at Petrified Forest.

markings on petrified wood that run perpendicular to the grain of the wood
These trace fossils represent the work of insects on a living tree over 200 million years ago!

NPS/Marge Post

Trace Fossils

Some fossils are not actual remains of an organism, such as bones, teeth, leaves, and seeds. A trace fossil is a fossilized track, trail, burrow, boring, or other structure that records the presence or behavior of the organism that made it rather than a piece of the organism itself.

Last updated: April 17, 2016

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Mailing Address:

1 Park Road, PO Box 2217
Petrified Forest, AZ 86028


(928) 524-6228

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