AL 129-1
Encyclopedia
AL 129-1 is the fossilized knee joint of the species Australopithecus afarensis
. It was discovered in Hadar
, Ethiopia
by Donald Johanson
in November 1973.
It is estimated to be 3-3.2 million years old.
Its characteristics include an elliptical Lateral condyle
and an oblique femoral shaft
like in humans, indicating bipedalism.
discovered the Hadar Formation in 1972. He then formed the IARE, inviting notably Johanson, an American
anthropologist now head of the Institute of Human Origins of Arizona State University
, and Yves Coppens
, a French born paleontologist now based at the Collège de France
to co-direct the research. An expedition was formed with four American and seven French participants, and in the Fall of 1973 the team surveyed Hadar, Ethiopia
for fossils and artifacts related to the origin of humans.
They found numerous fossils, but at first no hominids. Then, in November 1973, near the end of the first field season, Johanson kicked at what he thought was a hippopotamus
rib. He found that it was actually a fossil of a proximal tibia, the upper end of a shinbone. From its small size, he thought it was a monkey, and decided to collect it. While he was writing it up, he noticed a few yards away a distal femur, the lower end of a thighbone. This was split, so that it had only one of the condyles, or lumps making the knee joint. However, the other condyle lay next to it, and when he fitted them together and to the proximal tibia, the angle that the femur and tibia formed at the knee joint clearly showed that this was an upright walking hominid. This angular joint was in contrast to a monkey, which has the femur and tibia forming a straight line. Tom Gray walked up, and when shown the tibia on its own, thought it was a monkey, but when shown the angle formed with the tibia, agreed that this was from a hominid.
This was an immensely important find, as it would be the first showing upright walking hominids from 3 million years ago. On the day after finding the fossil Johanson was beginning to doubt his certainty, and there was an urgent need for confirmation as their agreement with the Ethiopian government required them to describe the finds at a press conference before they left. He did not want to botch his first important fossil interpretation, but they would not be allowed to take the fossil away for study unless he gave a description. That second evening he remembered a nearby ruin of an Afar burial mound. Comparison of the fossil finds with modern bones exposed by the collapsed side of the mound showed that, except for size, the bones were indeed virtually identical.
The team returned for the second field season in the following year and found hominid jaws. Then, on the morning of November 30, 1974, Johanson and Gray were searching in a gully about two and a half kilometres from the site where the knee joint had been discovered, when Gray found the first fossil fragment of Lucy (Australopithecus)
.
Australopithecus afarensis
Australopithecus afarensis is an extinct hominid that lived between 3.9 and 2.9 million years ago. A. afarensis was slenderly built, like the younger Australopithecus africanus. It is thought that A...
. It was discovered in Hadar
Hadar, Ethiopia
Hadar is a village in Ethiopia, on the southern edge of the Afar Triangle with a latitude and longitude of approximately . The village is known for the nearby archaeological site....
, Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
by Donald Johanson
Donald Johanson
Donald Carl Johanson is an American paleoanthropologist. Along with Maurice Taieb, and Yves Coppens he is known for the discovery of the skeleton of the female hominid australopithecine known as "Lucy", in the Afar Triangle region of Hadar, Ethiopia.-Early years:Johanson was born in Chicago,...
in November 1973.
It is estimated to be 3-3.2 million years old.
Its characteristics include an elliptical Lateral condyle
Lateral condyle of femur
The lateral condyle is one of the two projections on the lower extremity of femur. It is the more prominent and is the broader both in its antero-posterior and transverse diameters....
and an oblique femoral shaft
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
like in humans, indicating bipedalism.
Discovery
French geologist Maurice TaiebMaurice Taieb
Maurice Taieb, is a French geologist and paleoanthropologist who discovered the Hadar formation, recognised its potential importance to paleoanthropology and founded the International Afar Research Expedition...
discovered the Hadar Formation in 1972. He then formed the IARE, inviting notably Johanson, an American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
anthropologist now head of the Institute of Human Origins of Arizona State University
Arizona State University
Arizona State University is a public research university located in the Phoenix Metropolitan Area of the State of Arizona...
, and Yves Coppens
Yves Coppens
Yves Coppens is a French anthropologist. He graduated from the University of Rennes. He has studied ancient hominids and has had multiple published works on this topic, and has also produced a film....
, a French born paleontologist now based at the Collège de France
Collège de France
The Collège de France is a higher education and research establishment located in Paris, France, in the 5th arrondissement, or Latin Quarter, across the street from the historical campus of La Sorbonne at the intersection of Rue Saint-Jacques and Rue des Écoles...
to co-direct the research. An expedition was formed with four American and seven French participants, and in the Fall of 1973 the team surveyed Hadar, Ethiopia
Hadar, Ethiopia
Hadar is a village in Ethiopia, on the southern edge of the Afar Triangle with a latitude and longitude of approximately . The village is known for the nearby archaeological site....
for fossils and artifacts related to the origin of humans.
They found numerous fossils, but at first no hominids. Then, in November 1973, near the end of the first field season, Johanson kicked at what he thought was a hippopotamus
Hippopotamus
The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest...
rib. He found that it was actually a fossil of a proximal tibia, the upper end of a shinbone. From its small size, he thought it was a monkey, and decided to collect it. While he was writing it up, he noticed a few yards away a distal femur, the lower end of a thighbone. This was split, so that it had only one of the condyles, or lumps making the knee joint. However, the other condyle lay next to it, and when he fitted them together and to the proximal tibia, the angle that the femur and tibia formed at the knee joint clearly showed that this was an upright walking hominid. This angular joint was in contrast to a monkey, which has the femur and tibia forming a straight line. Tom Gray walked up, and when shown the tibia on its own, thought it was a monkey, but when shown the angle formed with the tibia, agreed that this was from a hominid.
This was an immensely important find, as it would be the first showing upright walking hominids from 3 million years ago. On the day after finding the fossil Johanson was beginning to doubt his certainty, and there was an urgent need for confirmation as their agreement with the Ethiopian government required them to describe the finds at a press conference before they left. He did not want to botch his first important fossil interpretation, but they would not be allowed to take the fossil away for study unless he gave a description. That second evening he remembered a nearby ruin of an Afar burial mound. Comparison of the fossil finds with modern bones exposed by the collapsed side of the mound showed that, except for size, the bones were indeed virtually identical.
The team returned for the second field season in the following year and found hominid jaws. Then, on the morning of November 30, 1974, Johanson and Gray were searching in a gully about two and a half kilometres from the site where the knee joint had been discovered, when Gray found the first fossil fragment of Lucy (Australopithecus)
Lucy (Australopithecus)
Lucy is the common name of AL 288-1, several hundred pieces of bone representing about 40% of the skeleton of an individual Australopithecus afarensis. The specimen was discovered in 1974 at Hadar in the Awash Valley of Ethiopia's Afar Depression. Lucy is estimated to have lived 3.2 million years...
.
See also
- List of fossil sites (with link directory)
- List of hominina (hominid) fossils (with images)
Further reading
- Johanson, D. C. and T. Taieb, 1976. A preliminary anatomical diagnosis of the first plio/pleistocene hominid discoveries in the central Afar, Ethiopia. Am. J. Phys. Anthropol. 45: 217-234.