THE LUNGFISH

In 1836, European scientists discovered a peculiar animal from the River Amazon that they struggled to identify. Its eel-like body was a few feet long and its air-filled lungs persuaded anatomists it must be a reptile.

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A year later, another specimen was found in Africa, and based on the structure of its heart, it was declared an amphibian. Three decades of debate later, scientific consensus settled on the idea that these are fish - only instead of breathing water through gills, they have lungs. Enter the lungfish.