Photo by Marge Post/NPS

Petrified wood represents trees once alive over 200 million years ago.

Fossils are clues to the past, allowing researchers to reconstruct ancient animals and plants. Together with the surrounding rocks, fossils tell the stories of ancient ecosystems.

Petrified Forest has plant and animal fossils representing the Late Triassic, 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.

Fossils can be big - some petrified logs found in the park measure over 190 feet - or small - a single tooth less than an inch long may contain the definitive characteristic of a new species.

Photo by Marge Post/NPS

Clam fossils from the Triassic Period indicate a waterway within the ancient environment.

Every fossil found is like a piece in a 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?

Context is very important with fossils. Where a fossil is found, what else it is found with, 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 tells its story.

When visiting the park, enjoy the petrified wood, but leave it where you find it. The park loses several tons of petrified wood each year through the acts of thoughtless visitors.

As part of the Petrified Forest National Park Learning Center, a monthly lecture series is held the first Wednesday of each month. Presentations will feature paleontology, geology, archeology, and other topics. Lectures are free and open to the public.

For more information on fossils, including educational resources for K-12 teachers, check out The Paleontology Portal website.

For more in-depth educational and scientific information about fossils visit the Society of Vertebrate Paleontology website, representing professionals, students, artists, preparators, and others interested in vertebrate paleontology.