Skull (cast) of a giant Mesozoic sea turtle, Protostega gigas, from Valley Anatomical Preparations, Canoga Park, CA.
Souvenir postcard from the Denver Museum of Natural History (now the Denver Museum of Nature and Science) showing a skeleton (ventral view) of Protostega gigas.
Vintage postcard from the Field Museum of Natural History (now The Field Museum) postcard reproducing in black and white Charles R. Knight’s mural portraying the mosasaur Tylosaurus vs. the giant sea turtle Protostega.