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AL 333, commonly referred to as the "First Family", is a collection of prehistoric hominid teeth and bones.

Discovered in 1975 by Donald Johanson's team in Hadar, Ethiopia, the "First Family" is estimated to be about 3.2 million years old, and consists of the remains of at least thirteen individuals of different ages.

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In the process of reworking, these ashes can pick up pre-existing detrital grains that, by definition, are older than the juvenile ash.

If during K-Ar analyses these detrital grains are not recognized and eliminated then they can cause the measured ages to be systematically too old.

The principal materials for dating East Africa hominid sites are volcanic ashes, yet many of these ashes are not deposited as primary air fall (Greek for ash).

Rather, most are reworked by stream action and are redeposited into the sedimentary environment.

The recovery of these 216 hominid specimens is unique in African paleoanthropology, since the close proximity of the different fossils suggests that these were individuals who might have lived in a group or been part of the same family.

Of the 216 specimens, 197 were surface finds, and 19 were found within 80 cm in the ground, suggesting a common time of death.The most famous of the Hadar discoveries is Lucy, the most complete A. However, in 1975, this same formation also witnessed the discovery of numerous remains from another site, AL 333.These remains became known as the “First Family,” and represent at least thirteen different individuals, both adults and children.In 1972, Taieb invited Yves Coppens, a French paleontologist, Jon Kalb, an American geologist, and Donald Johanson, an American anthropologist, to survey the region in order to appraise the area’s field exploration potential.They soon settled on working in the Hadar Formation, a sedimentary geological formation within the region. This is an informational tour in which students gain a basic understanding of geologic time, the evidence for events in Earth’s history, relative and absolute dating techniques, and the significance of the Geologic Time Scale.

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