Fossilized Pregnant Plesiosaur: 78-Million-Year-Old Fossils of Adult and Its Embryo Provide First Evidence of Live Birth
"A paper to be published on August 12, 2011 in the the journal Science reveals that Dr. F. Robin O'Keefe of Marshall University in Huntington, W.Va. and Dr. Luis Chiappe, Director of the Natural History Museum's Dinosaur Institute, have determined that a unique specimen now displayed in NHM's Dinosaur Hall is the fossil of an embryonic marine reptile contained within the fossil of its mother." - Science Daily