They seem innocuous enough—at least, until they extrude their huge, terrifying proboscis, tipped with four, black fangs. Each one is lined with copper minerals, […] A bloodworm.

Bloodworms are known for their unusual fang-like jaws, which are made of protein, melanin, and concentrations of copper not found elsewhere in the animal kingdom. Scientists have observed how ...

Left: Image of the everted proboscis of Glycera dibranchiata with its four jaws exposed, Right: Scanning electron microscope image of a Glycera jaw (Matter/Wonderly et al.) (CN) — The good news about ...