Mary Anning discovered the first complete skeleton of a Plesiosaurus in December 1823.
In December 1823, Mary Anning made a seminal discovery off the coast of Lyme Regis—a complete Plesiosaurus skeleton. This discovery was monumental because it was the first of its kind, reshaping the understanding of marine reptiles and supporting the emerging theory of extinction. The find was initially met with skepticism, as some scientists did not believe such a creature could exist. However, the specimen was later validated by leading paleontologists of the time, showcasing Anning's skill and perseverance in the male-dominated field of science. The Plesiosaurus remains one of the most iconic fossils in paleontological history, cementing Anning's legacy as one of the pioneering figures in the field.