Scientists first found fossil gigantic spermatozoa of crustaceans ostracods that appeared on Earth 540 million years ago. This suggests that the oldest sex cells of living beings have been discovered on the planet. A scientific article about the discovery was published in the journal Proceedings of the Royal Society.
The found calcined shells were preserved in a piece of amber. Paleontologists were able to melt the petrified resin and find as many as 39 ostracods, among which were males, females and juveniles of crustaceans. Their sperm and soft tissues were also preserved. The finds date back to 100 million years.
The researchers were able to create high-resolution 3D images of ostracods, which allowed them to see both their reproductive cells and genitals. Scientists concluded that “the behavioral repertoire of reproduction, associated with significant morphological adaptations, remained unchanged for at least 100 million years and is a major example of evolutionary stagnation,” the article says. In addition, the discovery showed the ability of amber to preserve the soft parts of invertebrates.
Scientists have previously revised their understanding of the movement of sperm during fertilization. The study of sperm under a microscope made it clear that the sperm cell rotates around its axis during movement. According to biologists, this asymmetry allows achieving symmetrical and correct movement towards the ovum.