A team of researchers from the University of New South Wales (Australia) has discovered at the Riversleigh World Heritage Fossil Site, giant sperm preserved in small shrimp that would have lived on Earth at least 17 million years ago .
It is the oldest fossilized sperm ever found and, according to the study published in the journal Proceedings of the Royal Society B: Biological Sciences , its size would be even larger than the body of the male that accumulates it , but strongly entangled within of the sexual organs of these crustaceans, known as ostracods.
“The Riversleigh fossil beds in remote northwest Queensland have been the site of the discovery of many extraordinary prehistoric Australian animals, such as giant toothed platypuses and meat-eating kangaroos. But the discovery of sperm fossils, with sperm nuclei, was totally unexpected. Now it makes us wonder what other types of extraordinary preservation await to be discovered in these deposits, ”says Mike Archer, study leader who has been excavating this Australian site for more than 35 years.
Examination of the fossils under the microscope revealed that they contained the preserved internal organs of the ostracods, including their sexual organs, and within them, perfectly preserved giant sperm cells. Researchers say that sperm is 1.3 millimeters long , which is equal to or greater than the crustacean itself.
