100-Million-Year Old Giant Sperm Discovered By Scientists



Ludwig-Maximilians-Universitaet

The oldest ever sperm has been discovered by scientists who believe it’s around 100-million-years old.


Until now, the oldest ever fossilised sperm was found in a 50-million-year-old worm cocoon from Antarctica.


The new discovery was found within a new species crustacean called Myanmarcypris hui. It’s said to have lived in coastal and inland waters in what is now Myanmar, surrounded by trees that produced huge quantities of resin.


Dr Renate Matzke-Karasz, a geobiologist at Ludwig-Maximilians-Universitaet (LMU) in Munich, and her team analysed 39 ostracods trapped in a tiny piece of amber using 3D X-ray reconstruction.



Ludwig-Maximilians-Universitaet

But what produces this ‘giant sperm’, I hear you ask? Well, while most animals produce small sperm in large quantities, some things like fruit flies and modern-day ostracods (a type of crustacean) produce a small number of oversized sperm that actually ends up larger than them in size. I’m not sure if we’re supposed to be impressed or horrified with this knowledge…


The sperm recently discovered was stored in a pair of receptacles inside the female ostracod where it was waiting for the eggs to mature. Scientists believe it could be the earliest direct evidence of a completed insemination, reported The Independent


Speaking about their findings, Dr Matzke-Karasz said:



The most significant part of our story is that we can now show that using giant sperm for reproduction is something that can last long in Earth history. Previously, we were not sure if animals that ‘switched’ to using these giant sperm at a certain point in their evolutionary history are doomed to become extinct very quickly.


After all, these are enormous costs for the animals. Large sperm must be produced, the reproductive organs are much bigger than in other species, they take up a lot of space in the animal, and mating lasts long.


This is a lot of biological energy that must be allocated to reproduction – so you might think that this doesn’t make sense from an evolutionary standpoint. But in ostracods, it seemed to work for more than 100 million years.




Pixabay

She added that she believes that, from an evolutionary point of view, sexual reproduction with the aid of giant sperm must be a ‘thoroughly profitable strategy’ with it lasting for as long as it does.


The world of science is a funny old thing.


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