Scientists examining a fossilized ostracod in amber have discovered the world’s oldest sperm, 100 million years old. The oldest sperm before this was 50 million years old.
Scientists, who discovered an amber fossil the size of a postage stamp that has been perfectly preserved for millions of years in a mine in the north of Myanmar, found that there were millions of years old ostracod fossils in the amber, and began to examine their findings.
Since ostracodes are animals ranging in size from 0.2 to 30 mm, scientists used a light microscope to examine the fossils in question. Having identified 39 ostracodes in amber, 31 of which belong to a previously undiscovered Myanmarcypris hui species, scientists made the most exciting discovery inside a female M. hui.
Realizing that the female Myanmarcypris hui’s soft tissues were extremely well preserved, scientists discovered four eggs inside the animal, which was only 0.59 millimeters in size, and one sperm in its seminal nests. Using computed tomography to create a three-dimensional image of the sperm, paleontologist He Wang of the Chinese Academy of Sciences thus recreated the earliest animal sperm discovered in three dimensions.
According to the article published in the Proceedings of the Royal Academy B magazine, the world’s oldest discovered animal sperm is only 200 micrometers long but exactly 100 million years old. The earliest previously discovered sperm was a 50-million-year-old sperm found in a worm cocoon in Antarctica. The oldest ostracod sperm before the latest discovery was 17 million years old.