OLogy Cards > Trilobites

Trilobites

Long before dinosaurs, strange roach-like creatures called trilobites scurried along the ocean floor in search of food. Trilobite fossils are fairly common so you may find one on your next fossil hunting expedition. Trilobite fossils are important because they help us see what the ocean was like over 250 million years ago.

Stats

Pronunciation: TRY-lobe-eytz
Name origin: their bodies have three distinct parts or lobes
Age: Paleozoic; 570 to 250 million years ago
Size: most were 0.25 inch (0.6 centimeters) to several feet long
Characteristics: hard-shelled creatures, like large bugs, crawled on, burrowed in, and swam above the ocean floor in search of food.
Significance: These extinct animals' closest living relatives are horseshoe crabs.

Story

It's A Bird! A Plane! No, It's a Giant Trilobite!
Imagine swimming into a two-and-a-half-foot (0.75-meter) long creature that looks like a hissing cockroach! If you were swimming off the coast of what is now Manitoba, Canada, 445 million years ago, you may have run into such a creature.

In 1998, a team of Canadian paleontologists in Churchill, Manitoba excavated the biggest trilobite fossil ever found. In fact, this trilobite fossil is about two times the size of the average house cat. Paleontologists believe that over 445 million years ago, this now frozen landscape used to be a tropical paradise. This amazing discovery will help scientists understand more about the ancient creatures that once inhabited our oceans.

Stumper

Paleontologists believe that trilobites probably ate:

trash

fish sticks

whales

Correct!

Scientists don't know what trilobites ate for sure, but they believe they were scavengers, which means that they ate anything left behind on the ocean floor.

Fact or Fiction

Trilobite fossils are very rare and difficult to find.

Fact

Fiction

Scientists and amateur fossil hunters alike have discovered many trilobite fossils. You may even find a fossil of their molted skin.

Fact or Fiction

Like insects, trilobites are also considered arthropods.

Fact

Fiction

Fact

Trilobites are ancient arthropods. Like insects and crustaceans (crabs and lobsters), trilobites had an exoskeleton (a hard outer shell), jointed legs, and antennae.

Image credits: main image, courtesy of AMNH Department of Library Services 10254.

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