As lead scientist Renate Matzke-Karasz of German's Ludwig-Maximilian-University explained to USA Today, the paleontologists happened upon: "ancient sex with gargantuan sperm."
"We have here direct evidence of a recent mating," Matzke-Karasz added. "All the co-authors are still amazed by the findings."
The sperm-filled specimen in question is an ancient version of a mussel shrimp -- officially, it is an ostracod, a member of ancient class of crustaceans.
The fossilized semen has been termed "giant" because of its size relative to the ancient shrimp. Scientists say some strings of the sperm could stretch up to six-times longer than the male's body.
The sperm was balled up and shot, like out of a cannon, and then caught by the female shrimp -- all right before her untimely death. Agony and ecstasy, as they say.
The recently-sexed shrimp came to rest inside a fossil-filled cave -- one of many in Australia's vast Riversleigh World Heritage Fossil Site -- where she was perfectly preserved for 17 million years.
And just when the story couldn't be more ripe for sophomoric lunch table jokes, it is. How was the semen-catching shrimp so perfectly preserved? Scientists say: bat poop.
Gross or not, the researchers are rather pleased with their historic finding.
"These are the oldest fossilized sperm ever found in the geological record," study co-author and paleontologist Michael Archer bragged to the Washington Post. "It's staggering."
More icky details of the ancient sperm finding are revealed in the journal The Proceedings of the Royal Society B.