Fossils: ‘Little Foot' is a similar age to
'Lucy' *IMAGES*
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Nature
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Palaeontology
Embargo
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London: Wednesday 01 April 2015 18:00 (BST)
New York: Wednesday 01 April 2015 13:00 (EDT)
Tokyo: Thursday 02 April 2015 02:00 (JST)
Sydney: Thursday 02 April 2015 04:00 (AEDT)
Lucy and Little Foot, famous early hominins from a genus known as Australopithecus, may
have roamed the Earth at similar times according to a study in Nature this week. New
analyses of the minerals from the South African cave in which Little Foot was found suggest
a burial date of around 3.67 million years ago, which is contemporaneous with the date
assigned to the bones of Lucy, discovered in eastern Africa. The finding that the two species
occurred at the same time, despite having different features, raises new questions about the
relationships of our ancient relatives.
The cave that bore the nearly complete skeleton of Little Foot, or Australopithecus
prometheus, contained several Australopithecus fossils. Attempts to date the specimens have
been challenging, as the cave has experienced many episodes of deposition, erosion and
reworking. The new dates reported by Darryl Granger and colleagues are calculated by
measuring levels of radiogenic isotopes of aluminium and beryllium in the quartz that
surrounded the skeleton; these isotopes are formed by cosmic-ray bombardment and act as
clocks in the rocks. As well as dating the skeleton of Little Foot, this technique enables the
authors to date the earliest stone tools found in the same cave to around 2.18 million years
ago, a similar age to tools from nearby sites.
Article and author details
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New cosmogenic burial ages for Sterkfontein Member 2
Australopithecus and Member 5 Oldowan
Corresponding Author
Darryl Granger
Purdue University, West Lafayette, Indiana, United States
Email: dgranger@purdue.edu, Tel: +1 765 494 0043
DOI
10.1038/nature14268
Online paper*
http://nature.com/articles/doi:10.1038/nature14268
* Please link to the article in online versions of your report (the URL will go live after the embargo
ends).
Geographical listings of authors
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Canada
, France
, South Africa
& United States
IMAGES
Image 1
Caption: The skull of Australopithecus prometheus StW 573 (Little Foot), dated to about 3.7
million years ago.
Credit: Jason Heaton
Image 2
Caption: Stephen Motsumi, Laurent Bruxelles and Ron Clarke in the Silberberg Grotto at
Sterkfontein.
Credit: Francis Duranthon
Image 3
Caption: Artifacts from the Oldowan infill at Sterkfontein, newly dated to about 2.2 million
years ago.
Credit: Kathleen Kuman