Not a misspelling: sea momster

For several Mesozoic aquatic reptiles, evidence for life birth had been found, but, until recently, not including plesiosaurs. Now, viviparity for a Late Cretaceous plesiosaur,  a 78-million-year-old Polycotylus latippinus, has been reported [1]. A fossil sample of this “sea monster” has been discovered, including an adult female plesiosaur with a mess of small bones nestled in its abdominal area:  “Since those bones show no sign of having been ingested by the adult, the adult specimen is the only known pregnant plesiosaur fossil,” writes Adam Hadhazy in a recent Natural History samplings column with the title Sea Momster [2].

 The fossil, which was discovered in 1987, remained in storage at the Natural History Museum of Los Angeles County for a long time, but is now on display in the museum's Dinosaur Hall [2-4].

Keywords: paleobiology, dinosaurs, carnivorous reptile, pregnancy, fossil embryo

References and more to explore
[1] F. R. O'Keefe and L. M. Chiappe: Vivparity and K-selected Life History in a Mesozoic Marine Plesiosaur (Reptilia, Sauropterygia). Science August 12, 2011, 333 (6044), pp. 870-873.  
doi: 10.1126/science.1205689.
[2] Adam: Hadhazy: Sea Momster. Natural History October 2011, 119 (9), page 6.
[3] Jennifer Welsh: Oh baby! Ancient 'sea monster' was pregnant. LiveScience 8/11/2011
[www.msnbc.msn.com/id/44113293/ns/technology_and_science-science/t/oh-baby-ancient-sea-monster-was-pregnant/#.TrbR-HJ1qjI].
[4] Natural History Museum of Los Angeles County > Dinosaur Hall Is Open  http://www.nhm.org/site/explore-exhibits/permanent-exhibits/dinosaur-hall.