Fossil internal mold (or, steinkern) of a chamber of the ammonite *Grossouvrites* sp. from the Cretaceous Lopez de Bertodano Fm. of Seymour Island, Antarctica (PRI 61185). Specimen is from the research collections of the Paleontological Research Institution, Ithaca, New York. Longest dimension of specimen is approximately 8.5 cm. Model by Emily Hauf.