Fossilised sperm found in Antarctica is world's oldest, say scientists

50m-year-old worm sex cells are the oldest found by 10m years, but although incredibly well-preserved contain no organic material

The world's oldest fossilised sperm has been discovered in the wall of a worm cocoon found in Antarctica, raising scientists' hopes of recovering more extremely rare fossils of microscopic soft-bodied lifeforms.

The prehistoric sex cells belong to a class of earthworms and leeches called Clitellata, and date from 50m years ago, in the early Eocene period when the first horses, rhinos and sheep emerged.