A team of paleontologists has discovered what they say is the world’s oldest animal semen, frozen in a small crustacean in a resin spot in Myanmar 100 million years ago.
The oldest known examples of petrified animal sperm were only 17 million years ago, according to a team of experts led by Wang He of the Chinese Academy of Sciences in Nanjing.
Sperm have been found in ostracods, a species of crustacean that has existed for 500 million years and can now be found in many oceans, researchers said in an article published Wednesday in the prestigious Royal Society’s Proceedings magazine.
They were found in the body of a female specimen, indicating that she must have been fertilized shortly before being enclosed in the resin, experts said.
To make the find even more special, the sperm have also been described as “giants,”
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“This is equivalent to about 7.30 meters for a 1.70-meter person, so it takes a lot of energy to produce them,” Renate Macke-Carasch of the Ludwig Maximilian University in Munich, co-author of the study, told AFP. .
The ostracod is also a new species that scientists have called “Myanmarcypris hui”.
Quality over quantity
Fossilized ostracod shells are common, but finding a specimen with “soft parts” is rare, experts say.
During the Cretaceous period (about 145 to 66 million years ago), the ostracods in question probably lived in the coastal waters of present-day Myanmar, where they were trapped in a patch of wood resin.
Most men in the animal kingdom (including humans) typically produce tens of millions of small sperm, but for ostracods, it’s all about quality over quantity.
There are several conflicting theories about the evolutionary value of such giant sperm.
“For example, experiments show that in one group, high levels of competition between men can lead to longer sperm lives, while in another group, low levels of competition can also lead to longer sperm lives,” says Macke-Karas. .
This finding shows “that reproduction with giant sperm is not an evolutionary extravagance on the verge of extinction, but a serious long-term advantage for the survival of a species,” concluded Macke-Karash.