A strange and mesmerizing marine worm has recently gone viral online, and once you see it, you’ll understand why. This ...

About 500 million years ago, the Grand Canyon was a great sea, and among the creatures it harbored was a newly discovered type of penis worm, armed with many rings of teeth. Penis worms are marine ...

Scientists found the 500-million-year-old fossil of a "penis worm" in the Grand Canyon—and reconstructed how the creature would have used its strange mouth to feed. The newly discovered species of ...