The oldest sample of animal sperm was found in a piece of amber. The find is supposed to be at least 100 million years old. And the sample is recognized as the oldest that ever existed and known to science. The most impressive fact in the discovery was that the sperm cells are many times larger than the human ones, although in fact they may belong to a small shrimp crustacean organism.
The ancient bivalve mollusk had a modest size, it was only 0.6 millimeters. It belonged to the species of micro-crustacean ostracods. These organisms are known for having ten times the sperm count of their body. It may seem impossible, but the scientists have an evidence.
Microscopic sperm cells are twisted and are balls that can easily move along the reproductive path of a female ostracod. The scientists obtained these data using a micro-computed tomograph, having examined about 40 samples of the oldest species of crustaceans that lived on our planet.
Surprisingly, the cells preserved in amber still possess some of the reproductive traits that are observed in modern ostracods today. Several individuals survived in one piece of amber, and the scientists found that the seminal vessels of the female crustacean organism were in an expanded state that indicates successful copulation shortly before the ostracods were trapped in the amber trap.
The scientists managed to measure the sperm cells of ancient creatures. Their length is about 0.2 millimeters, it is one third of the body length of the ostracod itself. Previously discovered fossilized remains of these creatures gave the scientists the opportunity to assume the presence of giant reproductive chains in the body.
The find in amber confirmed their theory, allowing accurate calculations to be made. By the way, in 2014, in one of the caves in Australia, the remains of ostracods were discovered, they are at least 16 million years old. The new specimen found in Myanmar is older, it is about 100 million years old.