The fossils date back to 17 million years ago. And they belong to giant sperm that was released by tiny shrimp. A team that included members of UNSW Australian research group made the finding awhile back at the Riversleigh World Heritage Fossil Site.
These giant spermatozoa are actually larger than the bodies of the shrimps. According to one of the professors in the posse, it is definitely the oldest sample of sperm in the entire world.
“These are the oldest fossilised sperm ever found in the geological record,” says Professor Mike Archer, of the UNSW School of Biological, Earth and Environmental Sciences, who has been working at Riversleigh for more than 35 years.
The site, Riversleigh, is in Queensland (Australia), and contains one of the largest collections of fossil deposits. Most of the creatures unearthed from the pits include Australian mammals.
From giant platypuses to carnivorous kangaroos, there are so many strange and weird life forms among the muddy sludge. Each new finding is a revelation in itself.
“But the discovery of fossil sperm, complete with sperm nuclei, was totally unexpected. It now makes us wonder what other types of extraordinary preservation await discovery in these deposits,” ,” says Professor Archer.
This recent discovery took some time to process and the study has been published in the journal titled Proceedings of the Royal Society B. The structure and function of the sperms and the shrimps show complex mechanisms of reproduction and transfer of genetic material between males and females.
The species of sea life is very well-preserved in the primal ooze at Riversleigh. The discovery almost makes one wonder what else lies in store in the mud in future times. The small shrimps lived in a cave-like structure that had bat excrement in it.
“About 17 million years ago, Bitesantennary Site was a cave in the middle of a vast biologically diverse rainforest. Tiny ostracods thrived in a pool of water in the cave that was continually enriched by the droppings of thousands of bats,” says Professor Archer.
These prehistoric vampires helped in the preservation of the shrimp. It was by means of muscular pumps that the male shrimps injected the sperm into the female ones. And as for the bat excrement, it contained excessive phosphorus levels which may have a lot to do with the solidification of the shrimps.
“This amazing discovery at Riversleigh is echoed by a few examples of soft-tissue preservation in fossil bat-rich deposits in France. So the key to eternal preservation of soft tissues may indeed be some magic ingredient in bat dr.oppings,” says UNSW’s Associate Professor Suzanne Hand, who is a specialist in extinct bats and their ecological role in Riversleigh’s ancient environments
Such findings are indeed rare and only add to our incomplete knowledge. They point to the fact that truth is sometimes stranger than fiction. It is a miracle in itself that sperm that is larger than the physical state of the organisms could have existed in the distant past of the earth’s history.