In a paper by Harmand et. al. (1) from May 2015 it was announced
that stone tools found at west Turkana, Kenya, had been securely dated to 3.3M
years old, thus surpassing those from Gona in Ethiopia previously date to 2.6M
years by 700,000 years. In an interesting twist of fate the archaeologists who
made the initial find of surface lithics were in fact looking for the site of
the original find of Kenyanthropus
platyops located only a few 100m away.
Here’s the abstract:
Human evolutionary scholars have
long supposed that the earliest stone tools were made by the genus Homo and
that this technological development was directly linked to climate change and
the spread of savannah grasslands. New fieldwork in West Turkana, Kenya, has
identified evidence of much earlier hominin technological behaviour. We report
the discovery of Lomekwi 3, a 3.3-million-year-old archaeological site where in
situ stone artefacts occur in spatiotemporal association with Pliocene hominin
fossils in a wooded palaeoenvironment. The Lomekwi 3 knappers, with a
developing understanding of stone’s fracture properties, combined core
reduction with battering activities. Given the implications of the Lomekwi 3
assemblage for models aiming to converge environmental change, hominin
evolution and technological origins, we propose for it the name ‘Lomekwian’,
which predates the Oldowan by 700,000 years and marks a new beginning to the
known archaeological record.
The site location is:
Important because:
1. The stone tools pre-date the genus Homo and were not made
by any of our recent ancestors from the ever-more bushy hominin tree of life.
2. Stone tools found recently and
over the last 150 years, such as those from Riwat (ca. 2M years old), Pakistan
(2), the Quranwala Zone, Siwaliks (3) , Northwest India (2.6 M years old) and some
of the European finds such as the sub-Red Crag lithics from near Cromer (4) in the
UK (ca. 0.4-1.75M years old) and older finds from Norfolk (ca. 2-3M years old),
previously controversial, disregarded or
ignored may in fact, be genuine pre-mode 1 tools i.e. Oldowan/Acheulean. (personally,
I think of these as Mode 0).
What are the tools like:
To put it bluntly: very large (3-15kg)
and well.. primitive!
Core from the LOM3 site. Image source Harmand et. al. 2015 (1)
Harmand et. al. 2015 (1) Fig 5.
Original caption reads: a, In situ passive element/anvil (LOM3-2012-K18-2, 12
kg). b, Passive element/anvil (LOM3-2012 surf 60, 4.9 kg). Both anvils a and b
exhibit similar patterns of macroscopic wear consisting of superposed step
fracturing
However they do still show flaking
by both bi-polar and passive-hammer techniques
As the authors (1) say:
"The dimensions and the percussive-related features visible on the
artefacts suggest the LOM3 hominins were combining core reduction and battering
activities and may have used artefacts variously: as anvils, cores to produce
flakes, and/or as pounding tools. . . . The arm and hand motions entailed in
the two main modes of knapping suggested for the LOM3 assemblage, passive
hammer [which consists on the striking of a core held in both hands against
an anvil on the ground] and bipolar, are
arguably more similar to those involved in the hammer-on-anvil technique
chimpanzees and other primates use when engaged in nut cracking than to the direct
freehand percussion evident in Oldowan assemblages."
The more interesting question is where did these hominins get the idea from and what were they trying to achieve?
Well as Harmand et. al. point out
our nearest living relatives; chimpanzees, gorillas and orangutans use tools/similar
techniques to obtain food. Presumably our last common ancestor (LCA), with chimpanzees did so
too. However in the broad, braided highway of evolution leading to mankind a
change in cognition led our ancestors 3.3M years ago (and perhaps even earlier)
to make the leap to technical consciousness. This involved hitting one rock
against another with the intention of
producing a sharp cutting edge useful in stripping meat from a scavenged carcass
where no conveniently broken rock was immediately to hand.
So who were these hominins?
The lead author suggests either Kenyanthropus platyops or Australopithecus afarensis.
Kenyanthropus platyops. Image Credit: Pavel Svejnar
Reconstructed skulls of Au. afarensis. Specimens AL 444-2 and
AL 333. Photo credit: IHO/Kimbel.
Location of the Au. deyiremeda
site in Ethiopia. Image credit: Erin DiMaggio.
Australopithicus afarensis finds
have been made at Koobi Fora and Lothagam in Kenya; at Belohdelie, Maka, (both
Middle Awash) Fejej, Hadar, and Omo in Ethiopia; and at Laetoli in Tanzania.
Possible other sites include Sibilot Hill and, Ileret in Kenya and the specimens
assigned to Australopithecus
bahrelghazali from Bahr el Ghazal in Chad. The main sites are shown
on the map below:
Image source: Adapted from
Tattersall 1988 (6).
With respect to Kenyanthropus platyops the only specimen
of the species has been much disputed for example by Tim White (7). He
maintains and that, the specimen is a distorted and crushed example of
Australopithecus afarensis. Add to this the widespread distribution of Au. Afarensis (see map above) and the
limited and geographically distant Australopithecus
deyiremeda remains, it would be fair to conclude that the stone tools were
made by Au. afarensis.
Verdict:
1. Stone tools made 3.3M years ago by Au. afarensis.
2. These tools have important implications for evidence of tool use
outside Africa. Previously early stone
tools dating between 2 and 3M years old from Asia and Europe have been fiercely
attacked or ignored. Subsequent to this discovery many of these should be
reconsidered.
3. If human ancestors were making stone tools close on a million years
earlier than previously thought, what other cognitive abilities developed
earlier? Social organisation, art, and language capabilities spring immediately
to mind.
Considering that the Human
Accelerated Regions (HARs) of our genome appeared early after our split from
our last common ancestor with chimpanzees, and that these changes have been
linked to limb, eye, fore, mid and hindbrain development and thus may affect
the development of fine motor skills, language and the higher reasoning skills
seen in humanity. See post here for more detail.
References
1. Harmand, S, et. al. 2015. 3.3-million-year-old stone
tools from Lomekwi 3, West Turkana, Kenya. Nature 521, 310–315 doi:10.1038/nature14464.
Available from:
2. Rendell, H.R., Dennell, R.W. and Halim, M. 1989.
Pleistocene and Palaeolithic Investigations in the Soan Valley, Northern
Pakistan. British Archaeological Reports International Series 544.
3. Malassé, A.D. et. al. 2016. Anthropic activities in the
fossiliferous Quranwala Zone, 2.6 Ma, Siwaliks of Northwest India, historical
context of the discovery and scientific investigations. Comptes Rendus Palevol.
In Press, Corrected Proof Available online 27 January 2016. Retrieved from:
4. J. Reid Moir. 1921. On an Early Chellian-Palaeolithic Workshop-Site in the Pliocene "Forest Bed" of Cromer, Norfolk. The Journal of the Royal Anthropological Institute of Great Britain and Ireland Vol. 51 (Jul. - Dec 1921), pp. 385-418
4. J. Reid Moir. 1921. On an Early Chellian-Palaeolithic Workshop-Site in the Pliocene "Forest Bed" of Cromer, Norfolk. The Journal of the Royal Anthropological Institute of Great Britain and Ireland Vol. 51 (Jul. - Dec 1921), pp. 385-418
5. Haile-Selassie, Y. et. al. 2015. New species from
Ethiopia further expands Middle Pliocene hominin diversity. Nature 521, 483–488.
6. Ian Tattersall, et al. eds. 1988. Encyclopedia of Human
Evolution and Prehistory. Chicago: St James Press
7. White T. 2003. Early hominids -- diversity or distortion?
Science 299:1994-1996.
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