Microwear Analysis at Dmanisi

This month in the Journal of Human Evolution, a new study on the teeth of the Dmanisi Homo erectus has been published. A site in the Republic of Georgia, Dmanisi has yielded a vast quantity of hominin fossils dating to approximately 1.8 million years ago—even an elderly individual without teeth. The discovered crania are remarkably well-preserved, and have given scientists the ability to look at our evolutionary history with higher resolution.

Based on the skeletal remains, how can we ascertain specifics about hominin diet? For this particular study, researchers used microwear analysis on two molars from Dmanisi. Microwear analysis observes the patterning left on teeth by components of specific diets. As one example, tough silicates in plants leave identifiable traces, as do other silica-based sands that end up being chewed.

Comparisons in wear patterns were made with Dmanisi H. erectus and African H. erectus as well as the genus Australopithecus and earlier Homo, to get an idea of where the Dmanisi hominins fit in on the spectrum of microwear diagnostic traits. These diagnostic traits include heterogeneity of the tooth surface, as well as complexity in the roughness of the tooth surface. To give you an idea of general evolutionary trends, Australopithecines typically had larger teeth and thicker enamel to break down tougher, lower quality foods. As later Homo emerged, teeth tended to get smaller and enamel thinner.

The results indicated that the molars of Dmanisi Homo erectus were very similar to African Homo erectus in general. However, there were also characteristics found to be consistent with other earlier hominin species. Overall the authors cautioned against drawing conclusions with such a small number of teeth, saying that meaningful statistical results are unattainable based on the sample size.

According to authors, the wear patterns on the Dmanisi teeth are indicative of hominins that exploited a range of foods. It seems then that versatility and not specialization is what defines H. erectus in both Africa and Europe. The ability to take advantage of a larger resource base is no doubt one of the factors that allowed the first hominins to spread out across such an expansive area.

By Matthew Magnani

Pontzer, H., Scott, J.R., Lordkipanidze, D., Ungar, P.S. 2011.“Dental microwear texture analysis and diet in the Dmanisi hominins.” Journal of Human Evolution 61:683-687.

6 thoughts on “Microwear Analysis at Dmanisi

  1. 1.8 million? Wow! I did not no we had dating techniques that were able to go that far back. Do you know which technique was used?

  2. Homo is and was an omnivore.

    I’m not sure if you can really call the Dmanisi hominins Homo erectus. They appear to be a chronospecies in transition from Homo habilis to Homo erectus.

  3. “They appear to be a chronospecies in transition from Homo habilis to Homo erectus”.

    That has certainly been my impression almost from the time I first heard anything about them. Perhaps even with elements of Australopithecus. But it is very likely that it is difficult to discriminate 100% between each species anyway.

  4. i agree there is a slim chance of clear separation between the species we infere. however all i read about dmanisi suggested it was rather a relic or isolated population of an early erectus exploration wave. i have seen noone state there were anatomical reasons to think otherwise.

  5. mh, small sorry. i thought i read that, there is a supposed controversy between the age of the bones, that is to say the sediments they were in, also the remains are all fragmented and leave no hope for a good reconstruction,
    however there are a couple of skulls and from what i understood they look like somewhat degenerate erectus. ofcourse nothing is sure but i am somehow convinced erectus in africa would tend to be less traced than outside it. i also find the idea africa just provided the major best evolution opportunitys for hominids during most if not all our evolution quite convincing.

    earlier i read dmanisi was a find in a rather calcite area with even fossil caves(pits), or similar structures. i would think people would have reported a disturbed sediment but perhaps they overlooked a thing, radioactivity from a soil or watersource, or the turbulence or the regional geology. it used to something aking to a lakeside, well, lakesides caves and sediments in calcite make for easy mixing.

    interesting idea still, for me mostly because it suggests erectus travelled far and wide, yet also it suggests we can expect more early fossils from africa, and other areas,

    it is even a bit of a problem when this is not the case, i would start out with an investigation of the dmanisi context unfortunately. for now the scenario advanced habilis suddenly ran to the caucasus to through disease or sudden developments consecutively run back to africa to evolve on and overtake the continents next is a bit much. otoh that erectus arrived at a few more places on earth we don’t know off yet would hardly surprise me nor would it be really surprising if they speciated, on a dental scale for example there are comparisons between chinese erectus and chinese over others, dminisova (unless someone traded them a mummified chimpansee or so ..) and neanderthal show hominids could untill recently physically specialise.

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