image: Life reconstruction of the plesiosaur Polycotylus latippinus giving birth to a single, large young, based on fossil evidence from the Upper Cretaceous (80 million years ago) of Kansas. Plesiosaurs were apparently unique among marine reptiles living during the age of dinosaurs in that they gave birth to single, large young, a trait more commonly associated with marine mammals rather than other reptiles. This image relates to an article that appeared in the Aug. 12, 2011, issue of Science, published by AAAS. The study, by Dr. F.R. O’Keefe of Marshall University in Huntington, WV, and colleagues was titled, "Viviparity and K-Selected Life History in a Mesozoic Marine Plesiosaur (Reptilia, Sauropterygia)." view more
Credit: Image courtesy of S. Abramowicz, Dinosaur Institute, NHM