World's oldest sperm discovered: 17-million-year-old cell is longer than its creator

 

Scientists have discovered the world’s oldest sperm: a ‘giant’ of a cell belonging to a species of tiny shrimp that lived 17 million years ago in what is now modern-day Australia.

The sperm is unusual not just for its incredible age but for being longer than the animal it was found inside; it managed to fit inside the shrimps’ sexual organs only by dint of being tightly coiled up.

“These are the oldest fossilised sperm ever found in the geological record,” said Professor Mike Archer of the University of New South Wales in a press release.

Professor Archer had been working at the same location for many years – a remote fossil deposit in northwestern Queensland known as Riversleigh – and has previously discovered other prehistoric animals at the site including a giant, toothed platypus and a flesh-eating kangaroo.

However, he says he was still shocked by the discovery of the sperm nuclei, describing the find as “totally unexpected” and adding “it now makes us wonder what other types of extraordinary preservation await discovery in these deposits.”

An artist's impression of the site 17 million years ago (complete with defecating bats). Image credit: Dorothy Dunphy

The survival of the animals’ soft tissue over such a long period of time is also rare, and is thought to be thanks to a “steady rain of poo from thousands of bats” in the pool where the shrimp were discovered.

It's likely that it was the high level of phosphorous in the animals’ faeces that not only killed off the tiny shrimp in the first place, but that also helped with the mineralisation process that preserved their soft tissues, with similar examples of 'preservation-by-poo' found in France.

The fossils in Riversleigh belong to a species of freshwater crustaceans known as ostracods and were originally collected in 1988. Years later they were passed to European specialists who discovered the sperm and recently published their findings in the journal Proceedings of the Royal Society B.

A modern example of the ostracod crustacean. Image credit: Dr. Renate Matzke-Karasz

Once fully unravelled the length of the cells is thought to be around 1.3 millimetres – about the same size or slightly longer than the shrimps themselves. This arrangement may sound unusual but is relatively common, with super-giant sperm thought to confer various evolutionary advantages in the biological arms race.

Fruit flies, for example, are just a few millimetres long but have sperm cells measuring six centimetres in length. This gigantism means that males can reproduce ahead of rivals by making sure there’s literally no space for any competing genetic material to get near the female’s egg.

Voices
voicesGood for Lana Del Rey for helping kill that myth, writes Grace Dent
News
The University of California study monitored the reaction of 36 dogs
sciencePets' range of emotions revealed
Life and Style
fashion Designs are part of feminist art project by a British student
Arts and Entertainment
The nomination of 'The Wake' by Paul Kingsnorth has caused a stir
books
PROMOTED VIDEO
Arts and Entertainment
The Tour de France peloton rides over a bridge on the Grinton Moor, Yorkshire, earlier this month
film
News
Snoop Dogg pictured at The Hollywood Reporter Nominees' Night in February, 2013
people... says Snoop Dogg
News
i100
Life and Style
food + drinkZebra meat is exotic and lean - but does it taste good?
Arts and Entertainment
Residents of Derby Road in Southampton oppose filming of Channel 4 documentary Immigration Street in their community
tv
Voices
voicesSiobhan Norton on why she eventually changed her mind
News
ebookA unique anthology of reporting and analysis of a crucial period of history
News
i100
Extras
indybest
Sport
Scottish singer Susan Boyle will perform at the Commonwealth Games opening ceremony in Glasgow
commonwealth games
Arts and Entertainment
Dwayne 'The Rock' Johnson stars in Hercules
filmReview: The Rock is a muscular Davy Crockett in this preposterous film, says Geoffrey Macnab
Life and Style
tech
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

BI Manager - £50,000

£49000 - £55000 per annum + competitive: Progressive Recruitment: My client is...

BI Project Manager - £48,000 - £54,000 - Midlands

£48000 - £54000 per annum + Benefits package: Progressive Recruitment: My clie...

VB.Net Developer

£35000 - £45000 per annum + competitive: Progressive Recruitment: If you're pa...

SAP Business Consultant (SD, MM and FICO), £55,000, Wakefield

£45000 - £55000 per annum + competitive: Progressive Recruitment: SAP Business...

Day In a Page

Noel Fielding's 'Luxury Comedy': A land of the outright bizarre

Noel Fielding's 'Luxury Comedy'

A land of the outright bizarre
What are the worst 'Word Crimes'?

What are the worst 'Word Crimes'?

‘Weird Al’ Yankovic's latest video is an ode to good grammar. But what do The Independent’s experts think he’s missed out?
Can Secret Cinema sell 80,000 'Back to the Future' tickets?

The worst kept secret in cinema

A cult movie event aims to immerse audiences of 80,000 in ‘Back to the Future’. But has it lost its magic?
Facebook: The new hatched, matched and dispatched

The new hatched, matched and dispatched

Family events used to be marked in the personal columns. But now Facebook has usurped the ‘Births, Deaths and Marriages’ announcements
Why do we have blood types?

Are you my type?

All of us have one but probably never wondered why. Yet even now, a century after blood types were discovered, it’s a matter of debate what they’re for
Honesty box hotels: You decide how much you pay

Honesty box hotels

Five hotels in Paris now allow guests to pay only what they think their stay was worth. It seems fraught with financial risk, but the honesty policy has its benefit
Commonwealth Games 2014: Why weight of pressure rests easy on Michael Jamieson’s shoulders

Michael Jamieson: Why weight of pressure rests easy on his shoulders

The Scottish swimmer is ready for ‘the biggest race of my life’ at the Commonwealth Games
Some are reformed drug addicts. Some are single mums. All are on benefits. But now these so-called 'scroungers’ are fighting back

The 'scroungers’ fight back

The welfare claimants battling to alter stereotypes
Amazing video shows Nasa 'flame extinguishment experiment' in action

Fireballs in space

Amazing video shows Nasa's 'flame extinguishment experiment' in action
A Bible for billionaires

A Bible for billionaires

Find out why America's richest men are reading John Brookes
Paranoid parenting is on the rise - and our children are suffering because of it

Paranoid parenting is on the rise

And our children are suffering because of it
For sale: Island where the Magna Carta was sealed

Magna Carta Island goes on sale

Yours for a cool £4m
Phone hacking scandal special report: The slide into crime at the 'News of the World'

The hacker's tale: the slide into crime at the 'News of the World'

Glenn Mulcaire was jailed for six months for intercepting phone messages. James Hanning tells his story in a new book. This is an extract
We flinch, but there are degrees of paedophilia

We flinch, but there are degrees of paedophilia

Child abusers are not all the same, yet the idea of treating them differently in relation to the severity of their crimes has somehow become controversial
The truth about conspiracy theories is that some require considering

The truth about conspiracy theories is that some require considering

For instance, did Isis kill the Israeli teenagers to trigger a war, asks Patrick Cockburn