Trilobite (Three Lobes)

Trilobite

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What is a Trilobite?

Trilobites were fascinating, ancient sea creatures that lived hundreds of millions of years ago. They belonged to a group called arthropods, making them distant relatives of modern insects, spiders, and crabs. Trilobites were some of the first animals to have hard shells and are among the most famous fossils found today.

How big were Trilobites?

Trilobites came in many sizes. Some were tiny, only about 1 centimetre long, whilst others could grow up to 70 centimetres (over 2 feet). Most trilobites were around 2 to 7 centimetres in length.

What did Trilobites eat?

Trilobites had a varied diet. Some were scavengers, munching on dead plants and animals on the sea floor. Others were predators, hunting tiny worms and other small sea creatures. Some trilobites may have filtered food from the water, a bit like modern shrimp.

Trilobite appearance

Trilobites had hard, segmented shells that protected their bodies. Their shells were divided into three main parts (hence the name 'tri-lobite'): a head, a body, and a tail. Many had large, compound eyes, some of the most advanced eyes of their time. Some trilobites could even roll up into a ball to defend themselves!

Where did Trilobites live?

Trilobites lived in oceans all over the world. Their fossils have been found on every continent, including Europe, North America, Asia, and Australia. They preferred shallow, warm seas but could be found at many ocean depths.

Interesting facts

• The name 'trilobite' means 'three lobes', referring to the three sections of their body.
• Trilobites first appeared over 520 million years ago—long before dinosaurs existed!
• There are more than 20,000 known species of trilobites. Some trilobites had spines and horns for protection.
• Trilobites are completely extinct, but their fossils are common and often beautifully preserved.

Trilobite Facts

Pronounced: TRY-loh-bite

Name Means: "Three Lobes"

Length: 1 cm – 70 cm (most are 2–7 cm)

Diet: Scavenger, predator, or filter-feeder

Time: Cambrian to Permian Period (about 521–252 million years ago)

Fossils Found: Worldwide

Which family of animals did Trilobite belong to?

Trilobites were part of the class Trilobita, which is a group of extinct marine arthropods. They are distantly related to modern arthropods like insects, spiders, and crabs.

What other animals lived at the same time as Trilobites?

Trilobites shared their seas with other early creatures like brachiopods, sea scorpions (eurypterids), ancient fish, and nautiloids such as Endoceras.

Trilobite FAQ

Q1: What were Trilobites?

A1: Trilobites were extinct marine arthropods that lived for over 270 million years, dominating ancient oceans.

Q2: What did trilobites look like?

A2: They had hard, segmented shells, lots of legs, and often large, compound eyes. Some could roll up like an armadillo.

Q3: How big were trilobites?

A3: Most were 2 to 7 centimetres long, but some grew much larger (up to 70 centimetres)!

Q4: What did trilobites eat?

A4: Trilobites ate a variety of things, from tiny sea creatures to dead plants and animals.

Q5: Where did trilobites live?

A5: Trilobites lived in oceans all over the world, especially in shallow, warm waters.

Q6: When did trilobites go extinct?

A6: Trilobites went extinct about 252 million years ago, during the largest mass extinction in Earth's history.

Q7: How good were trilobite eyes?

A7: Some trilobites had incredibly advanced eyes for their time, able to see in almost every direction.

Q8: Are trilobites related to anything alive today?

A8: Yes, they are distantly related to modern arthropods like insects, spiders, and crabs.

Q9: Who discovered trilobites?

A9: People have found trilobite fossils for centuries, but scientists began studying them seriously in the 18th and 19th centuries.

Q10: Are there any complete trilobite fossils?

A10: Yes! Their hard shells fossilised well, so many beautifully preserved trilobite fossils have been found.