The nautilus is known as a living fossil, an ancient lineage stemming back over 500 million years, long before dinosaurs walked the earth.

Elephant teeth are physiologically fascinating. Best known are the tusks, which are in fact modified incisors. The molars are equally important; their wide, flat surface perfect for grinding vegetation.

Hermit crabs are found in terrestrial and aquatic environments, and seek out empty molluscan shells to use as a home. Unlike other crabs, they have soft, spirally-curved abdomens, rendering them defenseless without these shells.