trilobite

Everyday

1. A trilobite was a sea animal with a hard, jointed shell and many legs that lived about 520 to 250 million years ago; trilobites are now extinct and known only from fossils. tree →
2. A trilobite is also a fossil of one of these animals. tree →

In the lessons

In science lessons trilobites are famous fossils: their bodies had three lobes (a middle and two sides), they were arthropods, related to insects, spiders and crabs, and some had some of the first complex eyes. Because each kind lived at a certain time, trilobite fossils help date rock layers. Phrases: trilobite fossil, extinct trilobites.

Examples

• I found a trilobite fossil on the beach in Wales. tree →
• Trilobites crawled along the sea floor long before the dinosaurs. tree →
• A trilobite's body was split into three long parts. tree →
• Some trilobites could roll up into a ball like a woodlouse. tree →
• Trilobites had eyes made of crystal. tree →
• All trilobites died out about 250 million years ago. tree →
• The museum had a whole case of trilobites. tree →

Note

Pronounced TRY-luh-bite. Plural trilobites. The name means «three lobes». A woodlouse is NOT a living trilobite, even though it looks a bit like one.