Little Foot

Infobox fossil
catalog number = Stw 573
common name = Little Foot
species = "Australopithecus", species uncertain
age = 2.2 - 3.3 mya
place discovered = South Africa
date discovered = 1994
discovered by = Ronald J. Clarke

"Little Foot" is the nickname given to an extraordinarily complete fossil hominin skeleton found in 1994-1998 in the cave system of Sterkfontein, South Africa.

Discovery

The original Little Foot specimens were found by paleoanthropologist Ronald J. Clarke in 1994, while searching through bags of fossil bovid fragments at the site of Sterkfontein. These fragments came from the Silberberg Grotto, a large cavern within the Sterkfontein cave system. He spotted four left foot bones (the talus, navicular, medial cuneiform and first metatarsal) that were unmistakably hominin and most likely from the same individual. They were described as belonging to the genus "Australopithecus," and catalogued as Stw 573 [Clarke, R.J. and P.V. Tobias (1995). Sterkfontein Member 2 foot bones of the oldest South African hominid. Science 269, 521-524.] .

Due to the diminutive nature of the bones, they were dubbed "Little Foot". Dr. Clarke found further foot bones from the same individual in separate bags in 1997, including a right fragment of the distal tibia that had been clearly sheared off from the rest of the bone. Two fossil preparators and assistants of Dr. Clarke, Stephen Motsumi and Nkwane Molefe, were sent to the Silberberg Grotto to try and find the matching piece of tibia that attached to this fragment. Amazingly, within two days they found the remaining part of the bone protruding from the rock in the lower part of the grotto. Careful excavation by Dr. Clarke and his team lead to the uncovering of a complete skull and jaw in articulation, as well as other limb bones.

These were announced to the press in 1998, resulting in considerable media attention around the world [Clarke, R.J. (1998). First ever discovery of a well-preserved skull and associated skeleton of an "Australopithecus". South African Journal of Science, 94; 460-463.] .

Subsequent work has uncovered a relatively complete skeleton, including a complete forearm and hand in articulation, parts of the pelvis, ribs and vertebrae, a complete humerus and most of the lower limb bones. This sensational discovery is still being excavated and is likely to be far more complete than the famous "Australopithecus afarensis" skeleton, "Lucy", from the site of Hadar, Ethiopia.

Dating

The complex geology of Sterkfontein makes precise dating of Stw 573 difficult. There are no volcanic tuffs to ensure accurate radiometric dating, and the paleomagnetic sequences are incomplete. Further to this, there has been considerable debate in the scientific literature as to how old Stw 573 is. Estimates range from almost 4 Ma based on cosmogenic 26Al and 10Be radiometric dating [Partridge, T.C., Granger, D.E., Caffee, M.W. and Clarke, R.J. (2003) - « Lower Pliocene Hominid Remains from Sterkfontein », "Science", Vol. 300, pp. pp. 607 - 612. ( [http://www.sciencemag.org/cgi/content/abstract/300/5619/607 abstract] )] to 2.2 Ma [Walker, J., Cliff, R.A. and Latham, A.G. (2006) - « U-Pb Isotopic Age of the StW 573 Hominid from Sterkfontein, South Africa », "Science", Vol. 314, pp. pp. 1592 - 1594. ( [http://www.sciencemag.org/cgi/content/abstract/314/5805/1592 abstract] )] based on Uranium-lead dating. A magnetochronology estimate places the fossil at about 3.3 Ma [Partridge, T.C., Shaw, J., Heslop, D. and Clarke, R.J. (1999) - « [http://www.geo.uu.nl/Research/Paleomagnetism/publications/Partridge99.pdf The new hominid skeleton from Sterkfontein, South Africa: age and preliminary assessment] », "Journal of Quaternary Science", 14, pp. 293-298.]

References

See also

*List of fossil sites "(with link directory)"
*List of hominina (hominid) fossils "(with images)"

External links

* [http://www.talkorigins.org/faqs/homs/littlefoot.html Talkorigins page on Little Foot]