The giant sperm is believed to be longer than the male shrimp’s entire body, and was found tightly coiled up inside the sexual organs of the fossilised freshwater crustaceans, known as ostracods.
Researchers collected the fossil ostracods back in 1988, before passing them to specialists who realized they contained soft tissues and sexual organs. The incredible preservation could be the result of bat droppings inside a cave 17 million years ago. “Tiny ostracods thrived in a pool of water in the cave that was continually enriched by the droppings of thousands of bats,” says Archer. It’s thought that the droppings helped with the mineralization of the soft tissues. Archer says the discovery was “totally unexpected” and it “now makes us wonder what other types of extraordinary preservation await discovery in these deposits.” Source