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The First Land Animals

Since autotrophs are the basis of a food web, plants had to exist on land before self-sustaining ecosystems with animals were possible.

Cambrian sand dunes show a few tracks made by aquatic arthropods and gastropods.

The oldest known air-breathing land animal was an arthropod, a tiny millipede that lived 428 mya.

Arthropod footprints and remains become more common in the Late Silurian.

Arthropods were well-suited to be first on land:

Lightweight bodies.

Slim, strong legs.

Hard exoskeletons.

Silurian

Page 19

A modern millipede,

Haitobolus haitensis.

Image in the public domain.

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