<em>Cypideis salebrosa</em> (IMAGE) Smithsonian Caption Female (top) and male (below) of the ostracod Cypideis salebrosa. Note the male shell is more elongated than that of the female. This is thought to reflect the need to accommodate the large male genitalia (highlighted in blue). A team of researchers studied this specimen and others in the collections of the Smithsonian's National Museum of Natural History to better understand the role of sexual selection in extinction. Their findings were published in Nature on April 11. Credit M. João Fernandes Martins, Smithsonian Usage Restrictions News-media use of these photos in relation to this study is permitted with attribution. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.