The Grand Canyon is Full of Fossils!

By: Eva Hatch

As a Hatch family member, Eva has seen a lot of fossils!

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From human history to stunning views, the canyon has something for everyone, including those with a love of the prehistoric. I’m talking about fossils! 

The sedimentary rock layers in the Grand Canyon created the perfect time capsule of life from long ago. Then, the fast-flowing waters of the Colorado River and its drainages acted as the shovel that dug the capsule up allowing us to see what’s inside. So let’s dig in!

Ocean Fossils

Millions of years before the Grand Canyon came into existence, this area was an ocean teeming with life. Today, the canyon’s rock layers preserve images of that life. The canyon’s ocean fossils appear within a group of rocks called the Tonto group which includes Muav Limestone, Bright Angel Shale, and Tapeats Sandstone. Some ocean fossils you may find in Grand Canyon include:

• Brachiopods – These are clam-like creatures that would attach themselves to the ocean floor. In between their two shells, they had valve-like structures that allowed them to filter feed.

• Crinoids – Though they may look like a flower, they are actually animals. Their feather-like arms allow them to move around as well as filter feed. Those arms sit on top of a stem-like structure. Much like our spinal cords, crinoid stems are made up of discs stacked on top of each other. These discs are what we see fossilized in the canyon!

• Nautiloids – These ocean predators can best be described as squids with shells. Some of them have circular shells with a spiral inside them (similar to Ammonites) and some have almost cone shaped shells

• Stromatolites – These are some of the oldest fossils in the Grand Canyon at 1,200 million to 700 million years old! They may just look like layers of rock but they are actually layers of cyanobacteria! This bacteria helped to oxygenate the earth before plants.

• Trilobites – Trilobites are arthropods that look like a cross between a rolly polly and a horseshoe crab. They swam and crawled around the ocean floor scavenging for food or sometimes even hunting for smaller prey to eat. 

Land Fossils

After the ocean receded this area started to boom with life on land. Most of these fossils of plants and creatures living on land come in the form of trace fossils. They show the imprint of the thing being fossilized. Think of pressing a flower into clay and then removing the flower, the outline left behind is like a trace fossil. These fossils can be seen in a group of rocks called the Supai group, Hermit Shale and Coconino Sandstone. 

• Plants – Trace fossils of plants or single leaves are visible in some of the upper rock formations of  the Grand Canyon. Common examples include ferns, ginkgo leaves, and pine needles.

• Animal Tracks – While nothing quite as exciting as giant dinosaur tracks have been found in the canyon, plenty of small animal tracks have been found. Trails left by scurrying scorpions, spiders and other bugs, as well as lizards and ancient reptiles can be seen among the rocks.

Honorable Mention

A fossilized Giant Ground Sloth skull was found within a Grand Canyon cave. These sloths were around nine feet tall!  They were herbivores that survived off of the native vegetation in the area. Although the skull has been removed from the park, this is still a fun fossil find in the Grand Canyon!

Learn more about Grand Canyon’s fossils from the National Park Service. OR… If you’re ready to become and up close and personal fossil hunter, join us for a rafting expedition!