From Ardi, one of the first human ancestors whose bones show evidence of walking on two feet, to the relatively recent skeleton of Cheddar Man, these famous fossils expanded knowledge of our origins in unexpected ways.
Our search into human origins is long and storied, with each fossilized discovery taking researchers in new directions. But a few fossils have allowed scientists to make such huge leaps forward in our understanding of human evolution that they earned indelible nicknames in our culture, like Lucy, who was discovered 50 years ago this month. These nicknames somehow make each fossil, even if it is just a small part of a skeleton, into an identifiable character in the story of humankind.
Here are 10 such fossils (presented in order of their age, oldest to youngest) -- each famed for their anthropological significance.
One of the oldest hominin fossils ever found was unearthed in 1994 by a team of scientists led by paleoanthropologist Tim White. The partial skeleton was located in Ethiopia and declared a new species, Ardipithecus ramidus, nicknamed "Ardi." The foot bones from Ardi and a reconstructed pelvis from another specimen of the same species hinted that this ancient, ape-like hominin was adapted to both tree climbing and walking on two feet.
Dated to around 4.4 million years old, the fossil was found alongside plant remains that suggested Ardi lived in a forest, a finding that discounted the "open savanna" theory of human evolution. The theory argued that bipedalism developed because the climate became drier, and hominins began to live on plains, where it was easier to move quickly and see over tall grasses on two feet instead of four.
The fossil nicknamed "Little Foot," found in Sterkfontein cavern in South Africa, is at least 3.67 million years old -- the oldest such specimen from the area known as "the Cradle of Humankind."
In 1994, paleoanthropologist Ron Clarke was sorting through some boxes of animal bones recovered from Sterkfontein cavern in 1980 when he realized he was holding four foot bones from an early species of Australopithecus, whom he dubbed "Little Foot." Three years later, as he examined a box of monkey fossils, he found bones from Little Foot's other leg -- which made him believe the entire skeleton might still be found in the cave. Clarke's assistants Stephen Motsumi and Nkwane Molefe returned to the cave and, within just two days, identified another part of Little Foot's leg buried deep in the cavern. Excavating the full skeleton took 15 years, but now, Little Foot represents the most complete Australopithecus skeleton ever found.
Lucy, dubbed "the Mother of Humanity," is probably the most famous hominin fossil in the world. In 1974, anthropologist Donald Johanson and his research student Tom Gray were working in a dry ravine at Hadar in the Afar region of Ethiopia when they noticed a small fragment of arm bone that looked like it came from a human-like creature. The pair quickly began searching for other bones in the area and uncovered 47 fossils, amounting to around 40 percent of a skeleton of the same individual.
Overjoyed at their find, they returned to camp and celebrated with colleagues at a party where The Beatles' song "Lucy in the Sky with Diamonds" played on repeat, inspiring the name of their discovery.
Later analysis of Lucy's bones revealed them to be 3.2 million years old -- at that time, the oldest hominin ever found. Researchers agreed she was from a new species of human-like ape that they named Australopithecus afarensis, meaning "southern ape from Afar." One of the important findings regarding Lucy's skeleton is that she was clearly adapted to walk on two feet, and yet she still had a relatively small brain. This anatomy showed that the evolutionary leap to bipedalism occurred before, not after, hominin brains became larger.
Workers at a quarry in Taung, South Africa, uncovered a remarkable skull in 1924, during an era when the location for the origin of modern humans was contested. Most researchers considered Southeast Asia to be the most likely contender thanks to the discovery of Java Man (more on him later) in the 1890s.
The workers brought the skull to paleoanthropologist Raymond Dart. When he began his analysis, he soon realized it was a very ancient hominin, and proposed that it supported Charles Darwin's theory that humans originated in Africa. Dart named the new species Australopithecus africanus ("southern ape from Africa").
The teeth in the skull confirmed it had belonged to a child of about 3 years old, and the position of the hole at the base of the skull where the spinal cord would have attached to the brain indicated that the Taung Child had walked upright. More recent research has pegged the fossil at 2.8 million years old. In 1995, paleoanthropologists Lee Berger and Ron Clarke proposed that claw marks under Taung Child's eye sockets suggested the toddler had been killed by a large eagle and brought to its nest, a hypothesis strengthened by the presence of eggshells and small animal bones found beside the skull.
As archaeologists Mary and Louis Leakey excavated a site at Olduvai Gorge in Tanzania in 1959, Mary caught sight of some enormous teeth sticking out of the sediment. The skull -- or what was left of it -- had been crushed into at least 400 pieces, requiring long and delicate work to extract them and complete a reconstruction. The skull eventually showed some incredible features: It had a huge, heavy jaw with molars twice the size of a modern human's, plus a sagittal crest -- an upraised line of bone across the top of the skull that helps anchor muscles for chewing, seen in modern-day gorillas. The Leakeys named their discovery Zinjanthropus boisei or "Zinj" for short, but the press soon nicknamed it "Nutcracker Man" due to its huge maxilla.
The skull, estimated to be 1.75 million years old, represented the oldest hominin discovered at that time. More recently the species has been renamed Paranthropus boisei and described as a branch of the human family tree, but not a direct ancestor of Homo sapiens.
In 1984, Kenyan paleontologist Kamoya Kimeu noticed a skull fragment sticking out of the silt of a dried-up riverbank in that country's Lake Turkana basin. He recognized it immediately as a Homo erectus fossil. Careful excavation uncovered more bones and, eventually, an almost complete skeleton with only the feet missing. The remains were around 1.5 million years old -- yet the 7- to 12- year-old child they came from had a skeleton surprisingly similar to a modern human.
The anatomy was unlike Lucy, whose skeleton revealed an ape-like creature with a small brain that could walk on two feet, with powerful arms and a funnel-shaped chest that suggested she still spent a great deal of time in the trees. Turkana Boy, in contrast, had a much larger brain, a barrel chest, and a tucked-in pelvis that demonstrated he walked upright, leaving his hands free to hold tools or wield a spear.
Dutch anatomist and geologist Eugène Dubois traveled to Indonesia in the 1890s with the hope of finding the ancestor of modern humans in Southeast Asia. While excavating near a river in Trinil, on the island of Java, Dubois uncovered a skull portion and a femur from the same individual. Noting the small brain size and strong brow ridges combined with the comparatively modern leg bone, Dubois concluded that he had unearthed a new, bipedal species of hominin, which he named Pithecanthropus erectus -- popularly nicknamed "Java Man." Dubois believed his discovery could be the so-called "missing link" in evolution between apes and humans, but closely guarded his fossils and refused to let anyone else examine them. Some colleagues accused him of fabricating a hoax.
After Dubois's death in 1940, American biologist Ernst Mayr was able to study the skull, and he concluded in 1944 that Java Man actually represented a fossil of Homo erectus. A 2020 analysis of Java Man's skull dates it to 1.3 to 1.5 million years old, which disrupts the theory that Homo erectus emerged in Southeast Asia. Earlier Homo erectus specimens dated to 1.85 million years old have been found in the Caucasus, suggesting that they evolved in Africa and traveled to Southeast Asia through Central Asia.
Between 1929 and 1937, Chinese scientists carried out excavations by candlelight in the Zhoukoudian district of Beijing (formerly Peking), China, that yielded a complete hominin skull cap, dubbed "Peking Man." The thick brow and sloping forehead pointed to the skull coming from the extinct hominin Homo erectus and was dated to between 770,000 to 230,000 years old. The discovery launched the field of anthropology in China and provided some support for the theory (now disproven) that modern humans emerged in Asia rather than Africa.
Peking Man was lost during World War II, when an American ship agreed to take the fossils to the U.S. for safekeeping. The ship was attacked by Japanese forces and the protective case carrying the bones disappeared. Scientists today have only casts of the bones, making DNA or other advanced study impossible.
And yet, analysis of bone samples from other fossils found in the same cave continue to write a story. These samples were compared to the genomes of 12,000 living Chinese people and demonstrated that Peking Man had no living relatives, lending further support to the theory that multiple waves of hominins left Africa over thousands of years to varying success. Homo erectus arrived in China around a million years ago but became extinct; Modern Chinese people are actually descended from Homo sapiens who left Africa and arrived in China around 45,000 years ago, sufficiently adapted to survive.
One of the most mysterious hominin groups known to science is the Denisovans. Just a handful of small fossil specimens of them have ever been found, and scientists continue to analyze these bits as much as technology allows. Researchers were amazed in 2018 when DNA sequencing revealed that one tiny fragment of bone, found on the floor of the Denisova cave in Siberia, belonged to a female teenage hominin with a Neanderthal mother and a Denisovan father. Researchers soon nicknamed her "Denny" and estimated that she lived around 50,000 years ago.
Denny's parentage proves that Neanderthals and Denisovans lived alongside each other, and studies have shown varying percentages of both Neanderthal and Denisovan DNA in humans living today. These exciting findings imply that both hominin groups also interbred with Homo sapiens who later out-competed them and contributed to their extinction.
No, he's not made of cheese. The fossil known as "Cheddar Man" was discovered in 1904 in Cheddar Gorge, Somerset, and represents the oldest and most complete skeleton of a modern human (Homo sapiens) ever found in Britain.
Cheddar Man lived roughly 10,000 years ago during the Mesolithic period, and recent analysis of his DNA has offered up surprising evidence about his appearance. Many anthropologists had believed that soon after Homo sapiens arrived in Europe around 45,000 years ago, their skin became naturally lighter, because pale skin is more efficient at absorbing UV light vital to Vitamin D production in places with less sunlight. However, DNA analysis of Cheddar Man revealed that his skin color was likely similar to people living in sub-Saharan Africa. Genetic signatures for blue eyes and dark brown hair were also present.