The remains of the oldest sexual intercourse in the world: giant sperm from 100 million years ago

The oldest remains of animal spermatozoa for which there is evidence date back to 100 million years, when the Earth was in the middle Cretaceous period, the climate was very hot and very humid, there were jungles even at the South Pole and dinosaurs they reproduced without stopping, according to a study published this week in the journal

.

The work, carried out by researchers from the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, shows that evidence of the sexual encounter was found inside a female of a tiny crustacean called an ostracod, trapped in Myanmar amber. .

This discovery is approximately 50 million years earlier than the oldest fossil record of animal sperm for which there was evidence, recorded 50 million years ago in the sperm of an Antarctic worm species.

According to scientists Wang He and Wang Bo, authors of the study, this type of ostracod belongs to a hitherto unknown species, named as

The set of these crustaceans found in amber and analyzed during the research is made up of 39 individuals and includes males, females and young.

The researchers used a computerized X-ray method to obtain high-resolution three-dimensional images of the soft tissue of the ostracods.

These analyzes provided direct evidence of female ovules and seminal receptacles containing giant sperm.

According to scientists, the length of these sperm is at least one-third the length of the body of the ostracod.

The researchers say that the female where the sperm appeared must have mated shortly before being trapped in the amber.

X-ray images also revealed semen pumps and a pair of tiny penises that male ostracods insert into females for reproduction.

Research further shows that the sexual behavior of this species has remained substantially unchanged for at least 100 million years.

"The emergence of a complex reproductive mechanism involving giant sperm enhanced mating success and may have been an important contributor to the conservation of the vast majority of non-marine ostracod species," the study reads.

Amber from Myanmar, an infinite source of discoveries

In what is now northern Myanmar, amber mines have been found that preserve with detail and accuracy the anatomy of more than 1,000 different species trapped 100 million years ago, 320 of them discovered in 2018 alone, according to the journal

In March this year, an international team of scientists from Chinese and North American universities published in the journal

the discovery of the remains of a carnivorous dinosaur smaller than a hummingbird.

The

, as it has been baptized, was preserved in amber from Myanmar, and was similar to a bird and with eyes similar to those of a lizard.

In 2019, scientists from Germany's Alexander Koenig Zoological Research Museum discovered a 99-million-year-old millipede also in Burmese amber.

The tiny organism measures 8.2 millimeters in length and was listed as the first fossil millipede of the order Callipodida, and also the smallest among its contemporary relatives.

In 2018, researchers from the Department of Integrative Biology at Oregon State University (United States) published an article in the journal

that reveals that the microorganisms that cause malaria and leishmaniasis were found in insects fossilized in this plant resin of Myanmar.

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