Paleontology at NHM

pregnant plesiosaur in dinosaur hall
This spectacular 15.5-foot wide and 8-foot-tall specimen is the only pregnant plesiosaur fossil ever discovered.

From Bone to Stone

Fossils are the evidence that paleontologists use to learn about life in the past. Fossils form only under very special conditions. Most animals and plants that die do not become fossils!

Fossils can form in many ways. Most dinosaur fossils were preserved through a process where bits of minerals in sediment fill in tiny open spaces in bone (or other organic tissue), slowly replacing the original material. Eventually, it becomes a rock in the shape of the bone!

Want to learn more? Click here to see how our Museum paleontologists excavate fossils in the field, as well as here at NHM!