These marine arthropods were present on Earth during the Paleozoic geological period and disappeared around 250 million years ago. If for a long time, very many trilobite fossils have been found, this is the first time that fossilized eggs have been discovered!
Trilobite fossils are highly prized by collectors. Indeed, this large family includes 18,000 different species, which implies very varied sizes and shapes of fossils. Scientists love them just as much because they are an excellent way to study a very ancient form of life.
On the other hand, the mode of reproduction of trilobites has always remained a mystery. Until recently, researchers couldn’t even identify their sex organs on fossils. Moreover, no one had ever found fully formed eggs. This lack was filled a few days ago with a unique discovery made in upstate New York.
This find was reported and detailed in ScienceDaily, whose source is none other than the Geological Society of America (GSA). The account describes several trilobite eggs, which vary in shape between specimens. These are either spherical or elliptical. Their size is around 200 micrometers.
Isolated, but also located inside the body of the trilobites, the eggs give information that scientists have been waiting for to be able to learn more about the reproductive system and the world of reproduction of the trilobites. Eggs inside the arthropod body were found near the head, a location reminiscent of the ovaries in horseshoe crabs, another genus of marine arthropods. Scientists believe that in the trilobite, the eggs were expelled through a genital opening (still unidentified) located near the back of the head
Sources: Science Daily – Sciences et Avenir