TED-ED: Jellyfish predate dinosaurs. How have they survived so long? - David Gruber

Jellyfish are ancient, diverse sea creatures with unique abilities. They lack a brain but have a simple nervous system and can propel themselves by contracting their bell. Some jellyfish have potent venom, while others glow due to GFP, a compound used in scientific research. Jellyfish have existed for over 500 million years and thrive in changing oceans. The immortal jellyfish can revert to a juvenile state, effectively bypassing death.

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