Discovery confirms the conclusions of the international research from 2009, in which the Czech researcher Radka Symonová from the Faculty of Science of Charles University also participated. Scientists then demonstrated the existence of so-called giant sperm in a study of the reproductive organs of 100 million-year-old fossils of bivalve molluscs from Brazil. But they did not find the preserved sperm then.
Giant sperm represent a high energy load for the organisms that produce them and occur in only a few animal species. Octomilks, for example, have a similar reproductive strategy as conch shells. Other animal species, including humans, have developed a different reproductive strategy that involves the production of large numbers of miniature sperm.