The hominid Lucy is a skeleton of the Australopithecus afarensis species discovered in Hadar, Ethiopia. It was at the time the oldest fossil record of a hominid: it dates back a little more than 3 million years.
In the traditional sense of the term, a hominid refers to modern humans and the fossils of their own evolutionary line. That is, the species that emerged after the separation with the chimpanzees.
Donald Johanson, discoverer of Lucy
In Lucy's case, it is a fairly complete young female skeleton. This hominid measured 1.1 meters and weighed about 29 kilograms.
This fossil is believed to represent the stage in which chimpanzees and humans diverged in their evolution.
Previous discoveries
Before Lucy's discovery, the first representatives of the Australopithecus genus had already been found. This genus includes species from southern and eastern Africa.
The name of this group of fossils was coined in 1924, after the discovery of part of a skull.
This appeared to have characteristics of both humans and apes, and clearly belonged to a creature that walked upright, depending on the position of the spinal cord.
Anatomist Raymond Dart turned his attention to the fossil, as it was unlike any creature he had ever seen before.
Dart proposed a new taxonomic category for his discovery: Australopithecus africanus. Furthermore, he suggested that this specimen represented an extinct form that was ancestral to humans.
With this he attracted all kinds of criticism from the scientific community. Science was not yet ready to accept certain theories.
For the next 50 years discoveries of new human ancestors were made from time to time. This included different species of Australopithecus.
But the multiple findings in the 1970s brought a new level of understanding regarding human origins. One of those great discoveries was the famous skeleton known as Lucy.
Lucy's discovery
On November 24, 1974, Donald Johanson and Tom Gray were returning from a morning fossil mapping and exploration journey at Hadar.
While taking a different route back to his vehicle, Johanson discovered a small part of an elbow bone. He immediately recognized that it came from a human ancestor.
Shortly after he saw an occipital bone, some ribs, a femur, a pelvis, and the lower jaw. It was obvious that the discovery was momentous, given that the sediments at the site were 3.2 million years old.
That night, hearing the Beatles song Lucy in the Sky with Diamonds, someone from the camp suggested naming the fossil Lucy. From the size of the skeleton they deduced that it was female.
Since then it is the name used for the oldest potential ancestor for each known hominid species.
Two weeks passed, and after extensive excavation, screening and sorting, hundreds of bone fragments were found. These represented 40% of a single hominid skeleton.
After 4 years, Lucy was officially described. It was a member of a new species called Australopithecus afarensis, and it was clear that it was one of the most relevant fossils ever discovered.
References
- Woolfson, MM (2009). Time, Space, Stars & Man: The Story of the Big Bang. London: Imperial College Press.
- Arsuaga, JL and Martínez I. (2006). The Chosen Species: The Long March of Human Evolution. Malden: Blackwell Publishing.
- Haviland, WA; Walrath, D.; Prins, H. and McBride, B. (2013). Evolution and Prehistory: The Human Challenge. Belmont: Cengage Learning.
- Rothman, L. (2015, November 24). How Lucy the Australopithecus Changed the Way We Understand Human Evolution. Retrieved on December 7, 2017, from time.com
- Institute of Human Origins. Arizona State University. (s / f). Lucy's Story. Retrieved on December 7, 2017, from iho.asu.edu
- Hogenboom, M. (2014, November 27). The 'Lucy' fossil rewrote the story of humanity. Retrieved on December 7, 2017, from bbc.com