Oldest jellyfish species revealed in fossils

Scientists have identified Burgessomedusa phasmiformis as the oldest known swimming jellyfish, based on fossil specimens recovered from the Burgess Shale in Canada. These animals lived more than 500 million years ago during the Cambrian period. Researchers classify them as medusozoans, the group that includes modern jellyfish, and say the fossils provide direct evidence that jellyfish-like animals had already evolved by that time.

The team, led by researchers at the Royal Ontario Museum, describe anatomical features such as a bell-shaped body and muscle impressions that suggest these animals were capable of free swimming and catching prey. At roughly 505 million years old, the fossils push back the timeline for when key jellyfish characteristics appeared. The discovery helps scientists understand early animal evolution and the ecological roles gelatinous predators played in Cambrian seas.

Who did it? And what's their angle?

Every conspiracy theory pins one culprit and one motive on the same story. The same story can spawn any number of theories — different culprits, different motives. That's part of how you spot a conspiracy theory: the same event can be "explained" any number of ways.

You'll walk through the four moves on separate screens, with a debunk on every step.