Tiny Shrimp, Giant Sperm

Arrows are pointing at the nuclei of the sperm cells. Image from http://www.sciencedaily.com/releases/2014/05/140513204635.htm, credit to R. Matzke-Karasz

However men around the world may hope to have the largest sperm to attest to their manhood, we have lost to an unlikely rival: shrimp. Discovered at the Riversleigh World Heritage Fossil Site by researchers from the University of New South Wales, these tiny crustaceans known as ostracods were almost perfectly preserved and fossilized.

These 17 million year old fossils were sent to a specialist ostracod researcher at La Trobe University, where it was discovered they contained soft tissue. This piqued the interest of the lead author from the Ludwig Maximilian University of Munich, who studied them with a researcher from European Synchotron Radiation Facility in France. A great display of international cooperation in the name of science!

Upon microscopic study, they discovered that the organs of the specimens were perfectly preserved, including the sexual organs, which contained the giant sperm cells. These sperm cells are believed to be 1.3mm, about the same length or longer than their father ostracod and are coiled up to fit within the Zenker organ, the organ responsible for pumping the sperm into the female. This makes the giant sperm cells the oldest ones yet!

So how then, do you think, did the shrimps get preserved so perfectly? Well the answer to this was, you guessed it, bat faeces (duh...). As the fossil site was located in a cave, the constant rain of bat poo increased the phosphorous levels of the water, making mineralisation of the soft tissue more efficient. This aided researchers in discovering other organisms that were also almost perfectly preserved, such as insects with internal muscles, leaf cells, as well as ancient mammals like giang, toothed platypuses and carnivorous kangaroos! All this was because the bacteria that wanted to digest these organisms were fossilised before being able to do so.

And so the moral of the story is: if you want to keep something forever, store it in a jar of bat poo!

What else do you think you think can be found at the fossil site? Also, what other compounds do you think are able to preserve organic material to this extent and why? Comment your answers down below and share the post if you have liked it!

Thanks for reading!

Reference:

1. R. Matzke-Karasz, J. V. Neil, R. J. Smith, R. Symonova, L. Mo kovsky, M. Archer, S. J. Hand, P. Cloetens, P. Tafforeau. Subcellular preservation in giant ostracod sperm from an early Miocene cave deposit in Australia. Proceedings of the Royal Society B: Biological Sciences, 2014; 281 (1786): 20140394 DOI:10.1098/rspb.2014.0394