![\"Artist\u2019s](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/08\/4_Artistic_view_Cretaceous_ostracods_Myanmar-138cbdb.jpg\" "\\"Artist\u2019s")
Artist\u2019s reconstruction of the Cretaceous ostracod crustacean Myanmarcypris hui male (right) and female (left) during mating. \u00a9 Dinghua Yang<\/p>\n100 million years ago during the Cretaceous period, in what is now Myanmar, ostracods living in a coastal lagoon, fringed by trees, had just had a sexual encounter when they became trapped inside the resin of a tree.<\/p>\n
Cocooned for millennia, encased in a coffin of amber, the microscopic crustaceans remained preserved in a time-capsule.<\/p>\n
Artist\u2019s reconstruction of the Cretaceous ostracod crustacean Myanmarcypris hui male (right) and female (left) during mating. \u00a9 Dinghua Yang<\/p>\n
But small though they may be, their discovery in 2020 was a big deal in the science world, and was hailed as a \u2018spectacular find\u2019 by scientists, as fossilised sperm are extremely rare \u2014 none previously discovered have been anywhere near as old as this. By comparison, the oldest known examples prior to this were a mere 17 million years old.<\/p>\n
The international study involved researchers from Queen Mary University of London and the Chinese Academy of Science. Their findings on the new, ancient, crustacean species, named Myanmarcypris hui, were published in Royal Society Proceedings B<\/a>. <\/p>\n Although finding fossil shells is not unusual, specimens that have been preserved so perfectly in ancient amber is very rare indeed.<\/p>\n Using x-ray microscopy and computer-aided 3D reconstructions of the ostracods embedded in the amber, the team were able to reveal incredible detail, and they were astonished by what they found. <\/p>\n \u201cThe results were amazing,\u201d said Dr He Wang of the Chinese Academy of Science in Nanjing<\/a>, who led the study. \u201cNot only did we find their tiny appendages to be preserved inside their shells, we could also see their reproductive organs.<\/p>\n \u201cBut when we identified the sperm inside the female, and knowing the age of the amber, it was one of those special \u2018eureka\u2019 moments in a researcher\u2019s life.\u201d<\/p>\n Although both male and female ostracods were found inside the ancient amber, the sperm was found in the female specimen, indicating a sexual encounter had just taken place shortly before the creatures were encased in their amber tomb.<\/p>\n \u201cAnalyses of fossil ostracod shells are hugely informative about past environments and climates, as well as shedding light on evolutionary puzzles, but exceptional occurrences of fossilised soft parts like this result in remarkable advances in our understanding,\u201d said Dave Horne, professor of micropalaeontology at Queen Mary University of London<\/a>.<\/p>\n Learn more about fossilised discoveries:<\/p>\n Ostracods as a species (also sometimes known as \u2018seed shrimp\u2019) have survived for more than 500 million years and live in a diverse range of aquatic environments, from deep oceans, to freshwater lakes and rivers.<\/p>\n The tiny crustaceans are less than a millimetre long and the males boast two penises. Although most other animal species opt for quantity over quality when it comes to sperm, producing tens of millions of minute sperm, ostracods (along with fruit flies) produce relatively small numbers of \u2018giant\u2019 sperm.<\/p>\n These sperm are many times longer than the animal itself, and exist coiled up inside the tiny crustaceans. <\/p>\n Finding giant sperm that is 100 million years old reveals the important discovery that even at this exceptionally early period in history, giant sperm had already evolved in ostracods, demonstrating that this must have been a highly successful reproductive strategy to have survived for so long. <\/p>\n![\"Beside](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/08\/2a_The_amber_piece_black_without_arrows-38a3916.jpg\" "\\"Beside")
Beside a few insects, thirty-nine ostracod crustaceans were entrapped in this tiny piece of Cretaceous amber found in Myanmar. He Wang and Xiangdong Zhao<\/p>\n![\"Reconstruction](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/08\/7_Fossil_sperm_reconstructed_1-98234c5.jpg\" "\\"Reconstruction")
Reconstruction of both sperm storage organs (seminal receptacles) of a female of the ostracod crustacean Myanmarcypris hui. They are filled with filamentous giant sperms, suggesting that the female had been inseminated shortly before it was trapped in resin. He Wang<\/p>\n