Amazing Discovery – A 50 million year old sperm of a worm found in Antarctica
The scientists have discovered 50 million year old fossilised sperm cells of a worm encased in a cocoon formed for the purpose of mating and reproducing.
1 An Accidental Discovery
As happens in many discoveries, this discovery is also something upon which the scientists just stumbled upon. Thomas Mors, a paleobiologust a t the Swedish Museum of Natural History, was looking for signs of small bones of mammals during an expedition in Antarctica, when he discovered a fossilized cocoon. He knew that mostly cocoons had some notable plant remains; he passed it to Benjamin Bomfleur, his colleague at the same museum. He started to look for some plants remains, but actually found some long and fragile remains of what seemed to be a sperm. He then passed the pictures to an expert of annelid sperms, Marco Ferraguti. He ascertained that it indeed was a sperm and through radiometric dating, he found that this sperm had actually been released 50 million years ago- the oldest sperm cell ever found. Through his collection of sperm pictures, he also found that is a Clitellata sperm from annelids
2 A connection between the living organisms of the Northern and Southern Hemispheres
The physical characteristics of the sperm matched with the sperms of a certain crayfish-worm, a tiny leech like creature that lives on the shells of crayfish feeding on dead organic matter. The interesting angle for the scientists came here, when they observed that crayfish worms today are found only in the Northern Hemisphere, and this sperm has been found in the Southern Hemisphere. The scientists now believe that this group of animals had a much larger geographical presence that time as compared to today.
3 The Reason of the sperm being preserved till date
Sperms are generally fragile and short lived, but this sperm is still there because of the biology of its creator. The ancient cocoons secreted a cocoon of about 2 millimetres of length which served a protective layer for eggs and sperms. The cocoon took several days to harden as it was formed by a sticky mucous, but once it hardened, it could encase sperms in its walls. And this exactly happened here. The sperm got stuck in the cocoon and could live till this this date.
4 Potential Downsides
One of the biggest downside to this astonishing discovery is that the sperm is not intact. It was found broken into fragments, making it a little difficult to collect great amounts of knowledge about the anatomy of the worm. Also the sperm has no organic matter present in it, ruling out any Jurassic Park style regeneration of an organism, but the finding of such an old sperm opens a lot of windows of hopes to find information about living beings that roamed the surface of the earth millions of years ago.
5 Hopes for some new discoveries
The team found also some other remnants of clam shells and small animals sticking to the cocoon. Bomfleur wrote a paper about this discovery in the Royal Society Biological Letters, in which he explained that worms as such do not fossilize well, so a sperm can actually give better clues when it comes to the creator of the cocoon. He hopes that such researches could encourage other people to come forward to look out for such structures.