Learn about a 480-million-year-old leech fossil that revealed that ancient leeches didn’t have the biological components necessary to suck blood.

Scientists have also long thought that the earliest leeches were bloodsuckers. All modern leeches, including species that do not consume blood, possess a suite of anticoagulants. But Macromyzon lived ...

A 430-million-year-old fossil has rewritten leech history, showing they are at least 200 million years older than previously ...