Thought Extinct for 40 Million Years | The Glass Sponge Reefs of the Deep

For most of the 20th century, science believed they were gone. Glass sponge reefs were known only from fossils — ancient structures from the Jurassic, extinct for 40 million years. Then, in 1987, a Canadian research team mapping the seafloor off British Columbia pointed a camera at an acoustic anomaly — and found a city made of glass.In this episode, we descend to 200 meters into the cold darkness of the Pacific Northwest to explore one of the most extraordinary rediscoveries in natural history. The Glass Sponge Reefs have been growing in unbroken darkness for 9,000 years, building eight-story structures from silica extracted molecule by molecule from the seawater itself. We break down the biology of an animal with no brain, no nervous system, and no individual cells — a creature that is, in a literal sense, one giant living fabric — and explain how it communicates and responds as a single organism without any of the machinery we associate with awareness.We follow the Venus Flower Basket to its strangest secret: the pair of shrimp that enter it as juveniles, grow too large to leave, and spend their entire lives together inside a glass cage — a relationship so perfectly mutual that the Japanese have given its skeleton as a wedding gift for centuries.And then we look at what happened when fishing nets reached the deep shelf. A sponge that takes 200 years to grow one meter tall. A trawl net that erases it in seconds.This is the story of something we almost destroyed before we knew it existed — and what it tells us about everything else we still haven't found.Secrets of Earth is a nature documentary podcast for all ages, exploring the why and how behind the planet's most extraordinary life.