While I do not believe we came from apes and monkeys I am always fascinated when they find unknown primates. The fossil record is so incomplete.
Lucy is the common name of AL 288-1, several hundred pieces of bone fossils representing 40 percent of the skeleton of a female of the hominin species Australopithecus afarensis. In Ethiopia, the assembly is also known as Dinkinesh, which means “you are marvelous” in the Amharic language. Lucy was discovered in 1974 in Africa, near the village Hadar in the Awash Valley of the Afar Triangle in Ethiopia, by paleoanthropologist Donald Johanson of the Cleveland Museum of Natural History.
The Lucy specimen is an early australopithecine and is dated to about 3.2 million years ago. The skeleton presents a small skull akin to that of non-hominin apes, plus evidence of a walking-gait that was bipedal and upright, akin to that of humans (and other hominins); this combination supports the view of human evolution that bipedalism preceded increase in brain size. A 2016 study proposes that Australopithecus afarensis was also to a large extent tree-dwelling, though the extent of this is debated.
“Lucy” acquired her name from the song “Lucy in the Sky with Diamonds” by the Beatles, which was played loudly and repeatedly in the expedition camp all evening after the excavation team’s first day of work on the recovery site. After public announcement of the discovery, Lucy captured much public interest, becoming a household name at the time.
Lucy became famous worldwide, and the story of her discovery and reconstruction was published in a book by Johanson. Beginning in 2007, the fossil assembly and associated artifacts were exhibited publicly in an extended six-year tour of the United States; the exhibition was called Lucy’s Legacy: The Hidden Treasures of Ethiopia. There was discussion of the risks of damage to the unique fossils, and other museums preferred to display casts of the fossil assembly. The original fossils were returned to Ethiopia in 2013, and subsequent exhibitions have used casts.
French geologist and paleoanthropologist Maurice Taieb discovered the Hadar Formation for paleoanthropology in 1974 in the Afar Triangle of Ethiopia; he recognized its potential as a likely repository of the fossils and artifacts of human origins. Taieb formed the International Afar Research Expedition (IARE) and invited three prominent international scientists to conduct research expeditions into the region. These were: Donald Johanson, an American paleoanthropologist and curator at the Cleveland Museum of Natural History, who later founded the Institute of Human Origins, now part of Arizona State University; Mary Leakey, the noted British paleoanthropologist; and Yves Coppens, a French paleoanthropologist now based at the Collège de France. An expedition was soon mounted with four American and seven French participants; in the autumn of 1973 the team began surveying sites around Hadar for signs related to the origin of humans.
In November 1971, near the end of the first field season, Johanson noticed a fossil of the upper end of a shinbone, which had been sliced slightly at the front. The lower end of a femur was found near it, and when he fitted them together, the angle of the knee joint clearly showed that this fossil, reference AL 129-1, was an upright walking hominin. This fossil was later dated at more than three million years old – much older than other hominin fossils known at the time. The site lay about 2.5 kilometres (1.6 mi) from the site where “Lucy” subsequently was found, in a rock stratum 200 feet (61 m) deeper than that in which the Lucy fragments were found.
The team returned for the second field season the following year and found hominin jaws. Then, on the morning of 24 November 1974, near the Awash River, Johanson abandoned a plan to update his field notes and joined graduate student Tom Gray to search Locality 162 for bone fossils.
Over the next three weeks the team found several hundred pieces or fragments of bone with no duplication, confirming their original speculation that the pieces were from a single individual; ultimately, it was determined that an amazing 40 percent of a hominin skeleton was recovered at the site. Johanson assessed it as female based on the one complete pelvic bone and sacrum, which indicated the width of the pelvic opening.
Lucy was 1.1 m (3 ft 7 in) tall, weighed 29 kg (64 lb), and (after reconstruction) looked somewhat like a chimpanzee. The creature had a small brain like a chimpanzee, but the pelvis and leg bones were almost identical in function to those of modern humans, showing with certainty that Lucy’s species were hominins that had stood upright and had walked erect.
