Ancient skull: A Homo erectus skullcap found northwest of Johannesburg has been identified as the oldest to date. The hominin, a direct ancestor of modern humans, moved out of Africa into other continents.
Stone Age chewing gum: This piece of birch pitch was chewed by a girl who lived 5,700 years ago in what's now Denmark. Geneticists were able to sequence her genome and oral microbiome from the substance. It was the first time human genetic material had successfully been extracted from something besides human bones.
Prehistoric Picasso: Maxime Aubert and Adam Brumm were part of the team that made the discovery of the world's oldest rock art found in a cave in Sulawesi, Indonesia.
Crazy beast: An artist's impression of Adalatherium, a bizarre mammal dubbed "crazy beast" and first described in 2020 is shown here. It would have lived among the dinosaurs and is unlike any other mammal -- extinct or living.
Primitive human ancestor: This is an artist's rendering of Ikaria wariootia -- a wormlike creature about the size of a grain of rice that was uncovered in South Australia. It's the oldest ancestor on the family tree that includes humans and most animals. The creature lived 555 million years ago.
Oldest material found on Earth: A magnified view of a presolar grain, or stardust, that is about 8 micrometers. It existed before our solar system was created.
Frozen bear: An Ice Age cave bear was found in Siberian permafrost with all its soft tissue intact. It could be up to 39,500 years old.
Voice from the dead: Researchers in the United Kingdom re-created the voice of a mummified Egyptian priest by 3D printing his voice box after scanning the priest's remains.
Viking diversity: A mass grave of around 50 headless Vikings from a site in Dorset, UK. Some of these remains were used as part of a massive DNA analysis of over 400 Viking skeletons. The study found that the Vikings were surprisingly genetically diverse.