Scientists have found the world’s oldest-known sperm, petrified and fossilized in an ancient bat cave at the Riversleigh World Heritage Fossil Site in northern Australia.

The 17 million year old sperm was discovered in a near-perfect state of preservation thanks to the high levels of phosphorous in the water, which could have aided mineralisation of the soft tissues, due to “the steady rain of poo from thousands of bats in the cave”, according to the researchers.

Professor Mike Archer, of the UNSW School of Biological, Earth and Environmental Sciences, who has been excavating at Riversleigh for more than 35 years, said:

“These are the oldest fossilised sperm ever found in the geological record”

Published in the latest issue of the Proceedings of the Royal Society, the paleontologists also described the sperm as “giant”, and at 1.3mm they are believed to be longer than the entire body of the Ostracoda, or mussel shrimp, that produced them.

Paleontologists have just discovered the world’s oldest-known petrified, fossilized sperm, according to a paper published in the latest issue of the Proceedings of the Royal Society B.

“The animal that produced these giant sperm belongs to the class of Ostracoda, or mussel shrimp,” lead author Renate Matzke-Karasz, a paleontologist at the Ludwig-Maximiliian University and Geo-Bio Center, told Discovery News, explaining that these hearty animals and their relatives have been on Earth for at least 500 million years.

Male mussel shrimp have industrial-strength sperm, which could explain why these animals have been around for so long. While it looks like angel hair pasta and strands are less than an inch in length, the sperm is enormous relative to the size of its male producer.