Gnathostomulida is an entire phylum of microscopic worms that live buried beneath the seabed.
They have no circulatory or respiratory systems, but they do have a fearsome set of jaws for scraping bacteria, fungi and protists from grains of sand.
There are lots of worms that would be terrifying if they were a few metres bigger. Some of them would just cut you in half, but it looks like this one would scrape the flesh from your bones.
That’s why biodiversity is important.
Images: Martin V. Sørensen