Phys.org has a story about Fiona, the pregnant ichthyosaur.  Fiona lived about 131 million years ago during the early Cretaceous Period.  Her remains were discovered a few years ago in a glacian ice field in Patagona.   Her story was published in a paper in the Journal of Vertebrate Paleontology.

Fiona is the only fully preserved and excavated pregnant ichthyosaur from Chile, and is the only known pregnant ichthyosaur from the Hauterivian, a time period during the Early Cretaceous. Her remains, which are complete and largely intact, provide a detailed look into the anatomy of ichthyosaurs, an apex marine predator that resembles a dolphin of today.

What’s more, the details about how Fiona—and 87 other ichthyosaurs in the glacial field—became buried in the seafloor could be part of a larger story of continental breakup, creating new ocean habitats, said study co-author Matt Malkowski, an assistant professor at The University of Texas at Austin’s Jackson School of Geosciences.

Malkowski, in collaboration with researchers at Boise State University, conducted the high-precision isotope dating that determined Fiona to be 131 million years old, a point in Earth’s history where South America was undergoing big changes. The continent was in the process of separating from what is now Africa. Malkowski said the opening up of a narrow oceanic passageway between the continents may have affected global climate, currents and habitats for marine life.