Paleontologists discover animal sperm 100 million years ago

  Paleontologists from China, Germany, and Britain recently discovered sperm from early animals in the Cretaceous Burmese amber 100 million years ago. This is the earliest animal sperm that has been discovered by humans so far, pushing the record time of animal sperm fossils by about 50 million years. Relevant research results were published in the British “Proceedings of the Royal Society Biology Branch” in the form of a cover paper on September 16.
  The ancient animal sperm discovered this time comes from a type of aquatic crustacean: ostracods.
  In this study, the scientific research team reported for the first time a soft-body ostracod fossil produced in Cretaceous Burmese amber. The amber weighs 0.676 grams and contains 39 ostracod fossil specimens. The largest ostracod individual is 0.59 mm and the smallest is 0.24 mm. The research team used high-resolution micro-tomography (micro-CT) to analyze 11 specimens. Through nearly a year of high-precision 3D image reconstruction, the shells and soft bodies of these ostracods were finely restored The morphological characteristics. Researchers found multiple ostracod sperm in the amber, which is the earliest known animal sperm. Further analysis and comparison show that the morphology of ancient and modern ostracod sperm is very similar, and its length can reach more than one-third of the ostracod body length, which is about 4 times the length of modern human sperm. This shows that the ostracods of 100 million years ago have been able to produce giant sperm and perform sexual reproduction as their offspring.