Terrawatch: clues of unexpected creatures in the ocean depths

Recently discovered fossil worm burrows reveal that, in the right sediment, life can survive far deeper than imagined

Blue Planet II gave us a glimpse of the weird and wonderful life that swims and floats in the deep ocean, but what about the creatures that live beneath the ocean floor? Present day surveys suggest that shrimps and worms inhabit the top tens of centimetres of seabed, but it was assumed that life couldn't survive much beyond 2m of sediment. However, recently discovered fossilised burrows show that, given the right kind of sediment, life can survive far deeper. Have we been looking in the wrong places for seabed critters?