This artist's illustration shows a young Purussaurus attacking a ground sloth in Amazonia 13 million years ago.
Jorge A. González
This bundle of bones is the torso of another marine reptile inside the stomach of a fossilized ichthyosaur from 240 million years ago.
Jiang et al.
Researchers uncovered the fossilized fragments of 200,000-year-old grass bedding in South Africa's Border Cave.
Lyn Wadley/Wits University
Meet Sasha, the preserved and reconstructed remains of a baby woolly rhinoceros named that was discovered in Siberia.
Stone tools made from limestone have helped researchers to suggest that humans arrived in North America as early as 30,000 years ago.
This image shows both sides of the 1.4 million-year-old bone handaxe made from the femur of a hippopotamus. It was most likely crafted by ancient human ancestors like Homo erectus.
This illustration shows Kongonaphon kely, a newly described reptile that was an early ancestor of dinosaurs and pterosaurs. The fossil was found in Madagascar. It lived about 237 million years ago.
Courtesy Alex Boersma
The Okavango Delta in Botswana showcases a patchy landscape where the ability to plan results in a huge survival payoff.
This is a clutch of fossilized Protoceratops eggs and embryos, discovered in the Gobi Desert of Mongolia. They provide evidence that dinosaurs laid soft-shell eggs.
These tools, made from the bones and teeth of monkeys and smaller mammals, were recovered from Fa-Hien Lena cave in Sri Lanka. The sharp tips served as arrow points.
This labeled map shows the complete ancient Roman city of Falerii Novi as it currently exists underground.
Fragments of the Dead Sea Scrolls found in the 1950s are seen here.
Najib Albina/Courtesy Israel Antiquities Authority
This is one of the 408 human footprints preserved at the Engare Sero site in Tanzania. The fossilized footprints reveal a group of 17 people that traveled together, likely including 14 women, two men and one juvenile male.
Blade-like stone tools and beads found in Bulgaria's Bacho Kiro cave provide the earliest evidence for modern humans in Europe 47,000 years ago.
This artist's illustration shows what an early, small ichthyosaur that lived 248 million years ago may have looked like. It resembled a cross between a tadpole and a seal, grew to be one foot long and had pebble-like teeth that it likely used to eat invertebrates like snails and bivalves.
This is an artist's illustration of Adalatherium hui, an early mammal that lived on Madagascar 66 million years ago.
This is an artist's illustration showing a cross-section of Earth's forming crust approximately 3 to 4 billion years ago.
Alec Brenner/Harvard University
Illuminated medieval manuscripts are full of intricate decorations, illustrations and colors, including "endangered colors" that can no longer be recreated today.