Satellite image of mouths of Amazon river in Brazil

Satellite image of mouths of Amazon River in Brazil, with Marajó Island in the center, and the cities (in red) of Macapá (left) and Belém (right) (NASA)

The mighty Amazon River has been hiding a secret that biologists have now revealed. Beneath the muddy waters, where the river meets the Atlantic Ocean, lies a unique and massive coral reef ecosystem. It stretches across thousands of kilometres and no-one had suspected it was there. We'll find out how we missed it, how it survives, and what might threaten it in the future.

Plus - baby dinosaurs with adult proportions; and a plant that attracts ants to fend off attacks from beetles.

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