Some trilobites could grow to nearly a metre in length!
Trilobites are an important group of extinct arthropods. Their bodies were divided into three segments: the head, body and tail. Although they looked like woodlice, and could roll into balls for protection, trilobites were more closely related to spiders and scorpions.
The majority of trilobites lived on the sea floor, though some could swim. Some large trilobites were active hunters, feeding on smaller, soft-bodied invertebrates.
Trilobites became extinct 250 million years ago, but even so survived for over half of the history of animal life. This first 250 million years of animal life is known as the Palaeozoic era.
You can see eyes and other fine detail on some well preserved trilobites.
The majority of trilobite fossils are small segments of their exoskeletons, rather than whole animals, but they can still tell us a lot. The huge number of trilobite fossils in many Palaeozoic rocks makes them useful to geologists and palaeontologists in a variety of ways.
The arthropods are split into different groups. Here we will look at the trilobites, crustaceans, insects and other fossil arthropods.
Other fossil arthropods
If you read these pages you should become an expert invertebrate identifier!
The major groups are listed below - select a link to learn more about this type of fossil.
Echinoderms Return to the wheel
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