Tiktaalik roseae, also known as the “fishapod,” is an animal that lived about 375 million years ago, with features of fish and four-legged animals.
The skull of Zinjanthropus is one of the first early hominid fossils found in Africa and provides essential clues in the story of human evolution.
A reconstruction of Anchiornis huxleyi, a feathered dinosaur that is part of the ancestral lineage of birds.
Adventurer naturalist Roy Chapman Andrews (center) inspects a nest of fossil dinosaur eggs in the Gobi Desert, Mongolia in 1925.
Many groups of organisms, including some diatoms, are radially symmetrical, and look like circles when seen end on.