Eurasian steppe chariots and social complexity during the Bronze Age

ba-eurasia-abashevo-sintashta

New paper (behind paywall), Eurasian Steppe Chariots and Social Complexity During the Bronze Age, by Chechushkov and Epimakhov, Journal of World Prehistory (2018).

Interesting excerpts (emphasis mine):

Nowadays, archaeologists distinguish at least three Bronze Age pictorial traditions on the basis of style, and demonstrate some parallels in the material culture. The earliest is the Yamna–Afanasievo tradition, which is characterized by the symbolic depiction of sun-headed men and animals. Another tradition is a record of the Andronovo people (Kuzmina 1994; Novozhenov 2012), who depicted in it their everyday life and the importance of wheeled transport (Novozhenov 2014a, b). Although petroglyphs on open-air natural rock surfaces are obviously hard to date, the occurrence of similar carvings on stone grave stelae within some Andronovo culture cemeteries (such as the Tamgaly Cemetery and the Samara Cemetery in Sary Arka, Kazakhstan) provide a level of chronological control. Finally, the finds of petroglyphs depicting chariots in the burials of the Karasuk culture (c. 1400–800 BC) in southern Siberia and Kazakhstan allow us to distinguish the latest tradition (Novozhenov 2014b).

petroglyphs-chariot
“Depictions of a chariot on the petroglyphs, the Koksu River valley, Kazakhstan (redrawn after Novozhenov 2012, p. 45, with the author’s permission)”

The site of Sintashta in the steppe zone of the Southern Trans-Urals (the eastern side of the Ural Mountains) was excavated in the 1970s and yielded abundant Bronze Age material, including unparalleled evidence of six vehicles buried in graves, each with two spoked wheels accompanied by cheekpieces and sacrificial horses (Gening 1977; Gening et al. 1992). (…) Chariot remains from the Middle and Late Bronze Age in the southern Urals are quite abundant compared with early chariot remains from other parts of the world, and allow statistical analysis.

In contrast, only two wagons and one sledge were found in the Royal Cemetery of Ur (Woolley 1965), and only ten actual chariots and their parts are known from tombs of the New Kingdom of Egypt (1550–1069 BC) (Littauer and Crouwel 1985; James 1974; Herold 2006), with the rest of the information on the Near Eastern chariots coming in other forms. Two chariots and the wheels of a third were also found in the Lchashen Cemetery in Armenia (Yesayan 1960), dated to 1400–1300 BC (Pogrebova 2003, p. 397), and bronze models of chariots were found in the burial sites of neighboring Transcaucasia (Brileva 2012). Over one hundred chariots have been discovered in Shang period tombs in China, but none dates before 1200 BC (Wu 2013).

Sintashta–Petrovka chariots were functional and used for carrying passengers and, probably, for warfare. Otherwise, one would not expect to see consistency in the measurements and technological solutions (…)

(1) The technological solutions used to construct a wheel and its dimensions are derived from the measurements of the ‘wheel pits’. They allow such analysis because some had the actual imprints of felloes and spokes. (…) Due to the imprints of spokes and felloes left in the soil, it is clear that the Bronze Age people knew of and utilized the spoked wheel.

(2) Wheel track is the distance between the centerlines of two wheels on an axle. It can be estimated on the basis of the distance between the central axes of all known wheel pits, in addition to direct measurement of the eight known cases of wheel imprints.(…) the majority of findings with a mean wheel track of 136 ± 12 cm might represent either a single-driver chariot or a vehicle with two passengers who accessed the vehicle from the rear, since one extreme of this wheel-track provides enough space for a standing person, while another is suitable for a driver and passenger.

(3) The means of traction is the element that connects the vehicle to the yoke of the draft animals (Littauer et al. 2002, p. xvii). It is needed for a vehicle to be pulled by harnessed animals and is constructed as a central draft pole located between the animals, or shafts located on the external sides of the animals, called thills. (…) Using burial chamber size as a proxy, chariots had a maximum estimated length of 327 ± 20 cm, and a maximum estimated width of 205 ± 21 cm. These dimensions suggest a great similarity to six chariots of Tutankhamun that have maximum dimensions of 260 × 236 cm (Crouwel 2013).

bridle-chariot-horses
Elements of Bronze Age chariots. Image from Chechushkov (2007).

Associated individuals

suggest that this person was a chief, and that the burial context illustrates his significance in the social life of the local community (Logvin and Shevnina 2008, p. 193). However, it also suggests the diverse role of the Sintashta–Petrovka elites, who were likely engaged in a number of different activities, such as warfare, craft production, food production, and a broad social life.

(…) while weapons are not universally present with chariots, they are present much more often than in non-chariot burials: more than 50% of the chariot burials are accompanied by weapons, with a clear predominance of projectile arms.

The creation, utilization, and maintenance of the chariots would have required a number of important skills, and some degree of standardization in manufacturing chariots might be related to a very small number of chariot makers. This means that the Sintashta–Petrovka craftsmen were ‘attached specialists’ and made their products following the orders and desires of those who were interested in the competitive use of chariots. Hence, the social group interested in producing and maintaining chariots sponsored all of those processes. While the nature of this social group is unclear, it is reasonable to hypothesize that it could be a group of military elites characterized by aggrandizing behavior. These people shared military identities and values, but also belonged to bigger collectives, presumably diverse kin groups. The competition between these collectives for resources, power, and prestige created the chariot complex.

Evolution

Analyzing horse-headed knobs, Kovalevskaya demonstrates the evolution of horse tack from a simple muzzle to a bridle with bits during the 5th and 4th millennia BC (Kovalevskaya 2014). Her analysis correlates well with a study of pathologies in horse teeth conducted by Brown and Anthony, who suggest the appearance of bits and horseback riding at Botai and Tersek (Anthony et al. 2006). Cheekpieces became the next necessary and logical step in the evolution of means of horse control. Their appearance together with the wheeled vehicles is not a coincidence, but the development of preceding tools. After the year 2000 BC, cheekpieces often occur together with sacrificed horses—13 out of 15 Sintashta burials with cheekpieces also contain horse bones (Epimakhov and Berseneva 2012)—showing evolution in the role of horses.

The whole paper offers an interesting summary of cultural and population events in the Pontic-Caspian steppes since the Early Yamna period. Also, horse-headed knobs!

NOTE. You can find similar information in other (free) papers from Chechushkov in his account in Academia.edu.

Related

Origin of horse domestication likely on the North Caspian steppes

Open access Late Quaternary horses in Eurasia in the face of climate and vegetation change, by Leonardi et al. Science Advances (2008) 4(7):eaar5589.

Interesting excerpts (emphasis mine):

Here, we compiled an extensive continental-scale database, consisting of 3070 radiocarbon dates associated to horse paleontological and archeological finds across the whole of Eurasia, that has been analyzed in association with coarse-scale paleoclimatic reconstructions. We further collected the number of identified specimens (NISP) frequency data for horses versus other ungulates in 1120 archeological layers in Europe (…) This ma.ssive amount of data allowed us to track,with unprecedented details, how the geographic distribution of the species changed through time

Geographic range through time

For most analyses, the data have been divided into climatic periods: pre-LGM(older than 27 ka B.P.), LGM(27 to 18 ka B.P.), Late Glacial (18 to 11.7 ka B.P.), Preboreal (11.7 to 10.6 ka B.P.), Boreal (10.6 to 9.1 ka B.P.), Early Atlantic (9.1 to 7.5 ka B.P.), Late Atlantic (7.5 to 5.5 ka B.P.), and Recent (younger than 5.5 ka B.P.) (Fig. 1, A and B). The spatial and temporal distribution of horse remains compiled in our database reveals a strong imbalance in Eurasia (Fig. 1, A and B).

We found a common trend in both regions for a high number of occurrences at the end of the Pleistocene (with a decrease during the LGM, only visible in Europe), followed by a drastic reduction in the Early and Middle Holocene, and a relative increase toward more recent times. These included both the Early Atlantic in Europe, which started ~9.1 ka B.P., and the time range after 5.5 ka B.P. for Asia. The horse fossil record appears ubiquitous throughout Europe in the Late Pleistocene, while in the Early and Middle Holocene the finds are concentrated in central-western Europe and Iberia. From 7.5 ka B.P., the number of finds increases markedly, and the geographical distribution extends toward the east and southeast.

horse-distribution-climate
Horse occurrences through time. (A) Horse occurrences through time. Histograms showing the number of horse observations in Europe (left panel) and Asia (right panel) for each time bin (top) and for climatic period (bottom). Only time bins with more than 10 observations (black horizontal line) have been considered for the SDM analyses. From 22 ka B.P. backward (gray vertical line), time bins cover 2 ka following the available paleoclimatic reconstructions. The central map shows the boundaries considered while defining European and Asian regions, with the black line representing the Urals. The zoomed area shows the geographical resolution of the climatic reconstructions, with each pixel representing a grid cell. (B) Geographic distribution of horse occurrences. Maps showing horse occurrences for each climatic period in Europe (left) and Asia (right).

Different Asian and European niches

This analysis revealed that, in both continents, horses occupied only a portion of the climatic space available. The range covered by random locations shows that the paleoecological conditions present in Europe were only a subset of those found in Asia. However, European horses occupied a much wider climatic space than in Asia, with only limited overlap between the two ranges.

Horses conquered temperate environments from a European source

There is no evidence of climatic barriers between those two populations through time because the forecasts from Europe and Asia always overlap in central Eurasia, except 5 ka B.P. (figs. S3 and S4). An alternative explanation is the role of the Urals as a potential constraint for the dispersal of horses between Europe and north central Asia.

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Climatic suitability. (A) Cumulative climatic suitability for the past 44 ka based on simulation on the European (left), Eurasian (middle), and Asian (right) data sets. To correct for sampling bias in the Eurasian data set, for each time slice, all estimates and projections for Eurasia are performed considering 100 random resampling of European occurrences in the same number as Asian occurrences. The darker the colors, themore stable the climatic suitability for horses (climatic niche = p-Hor) through time. (B) Projection of climatic suitability across Eurasia in different climatic periods based on occurrences in Europe (left), Eurasia (middle), and Asia (right). Because of the scarcity of data available for Asia, no models for the Holocene have been possible for both Asia and Eurasia, with the exception of 5 and 3 ka B.P. (both included in the “Recent” period).

Climatic and habitat association patterns for horses in Europe support increasing habitat fragmentation

The decrease of horse remains in Europe is not characterized by a geographic reduction in the overall extent of the area occupied by the species but in a drop of frequencies in a geographic extent that does not vary much between the Late Glacial and the Early Atlantic (Figs. 1B and 4B). This pattern is more likely to result from habitat fragmentation than from a geographic shift in the climatic range suitable for the species, as observed for many animals during the LGM (23).

In the whole period ranging from the Preboreal (11.7 to 10.6 ka B.P.) to the Late Atlantic (7.5 to 5.5 ka B.P.), the total amount of land space most and likely suitable to horses is wider than in the Late Glacial, and only between 8 to 7 ka ago the European range appears patchy and fragmented (Fig. 4C). When comparing each of four successive time bins during the Holocene (8, 7, 6, and 5 ka B.P., respectively) (Fig. 4E), the difference in successive p-Hor values in Europe shows that the suitability for the species in Iberia, northeastern France, Italy, the Balkans, and eastern Europe steadily increased, while in Central Europe strong differences can be observed between neighboring regions.

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Analyses of the European data set and biomefrequency. (A) Distribution through time of the frequency of horse remains in Europe calculated as NISP of horses versus other ungulates. (B) Density of horse remains through time in Europe, calculated as NISP of horses versus other ungulates. The numbers at the bottom of each bar represent the number of observations falling in each class, from 0 to >5%. (C) Climatic suitability for horses in Europe between 10 and 3 ka B.P. (D) Climatic suitability per time period. Percentage of land cells in Europe with a value of suitability for horses (p-Hor) > 0.5 and p-Hor > 0.8. (E) Holocene climatic amelioration. Difference in p-Hor in Europe comparing five successive time bins during the Holocene: 9, 8, 7, 6, and 5 ka B.P. Eachmap shows the difference in themore recent distribution compared to the previous one. (F) Environmental reconstructions in themacro area surrounding horse finds in Europe (left) and Asia (right) per climatic period. The lighter the color, the less forested is the region. The numbers at the bottom of the bars show the number of occurrences in closed environments over all the observations. The dotted line represents a frequency of 0.5.

Taken at face value, this pattern would suggest that horses were not restricted to open environments but could equally well inhabit closed, forested environments, as previously suggested (18). However, as others recently emphasized (19), the faunal associations inHolocene sites from Europe suggest a different pattern. The PCAs based on faunal assemblages (figs. S1 and S2) separate on the second principal component sites characterized by ungulates associated to forested areas (red deer, wild boar, and roe deer) and all other animals, associated to semi-open and open environments, including horses for most records.

Together, the contrast between the reconstructed microscale and macroscale vegetable coverage in Europe, the increase of horses in mainly forested macroregions, and the spatial pattern of extinction suggest that, from the beginning of the Holocene, the suitable environment became more and more patchy, with open areas increasingly fragmented by forests, where wild populations of horses could have survived in isolation until one or several waves of arrivals of domestic horses, leading to either local admixture or a full replacement of the preexisting local populations.

Conclusion

Our data show that, up to 5.5 ka ago, horse finds do not show association with species characteristic of forested areas such as wild boar and roe deer. We infer that the open and semi-open habitats occupied by horses on a narrow geographic scale appear less and less frequent at a macroenvironmental scale, supporting the possibility of increasing fragmentation of open habitats. This event is also likely to have led to an intensification of genetic isolation for the remaining horse populations, a pattern that still needs to be tested on genomic data.

The suitability of both Iberia and eastern Europe appears constant throughout the entire post-LGM period, in line with these regions being hotspots of genetic diversity and, possibly, the refugia sources for the recolonization of the continent (11). While the Pontic-Caspian region appears not suitable for European horses around the time when horses where first domesticated some 5.5 ka ago (6), part of this region appears suitable for the Asian horses (with the Caspian Sea as the westernmost boundary). This may suggest that horse domestication started from a population background related to an Asian ancestry and that the further spread of the domesticated horses in Europe involved either adaptation to novel niches (possibly through selective breeding) or the application of domestication techniques to local horse populations pre-adapted to these environmental conditions. Testing this scenario will require mapping the genetic structure of the Eurasian horse population within the fifth to third millennium BCE.

Some remarks

Cultural-anthropological research and archaeological remains (see here), genetics (see here and here), and now also thorough palaeoclimatic and archaeological models point to the North Caspian region, settled by the Khvalynsk culture, as the most likely earliest origin of horse domestication. The paper also supports the favorable conditions of western Europe up to Iberia for the introduction of a horse-riding culture.

I intended to write a post about the myth of Corded Ware horse riders, but for the moment I haven’t found the time. Not that Corded Ware pastoralists didn’t have horses, or could not ride them: they were a highly mobile culture of pastoralists stemming from eastern Poland / western Ukraine, so they must have known horses, like many other European cultures of the late 4th / early 3rd millennium influenced by expanding Yamna settlers. But it just cannot be said to have formed an essential part of their culture, as it was for Khvalynsk-Novodanilovka, and especially Yamna and later East Bell Beaker, Sintashta, etc.

A mere look at these maps suffices to assess the limited role of the horse in north-eastern Europe, the only region where groups of late Corded Ware-derived cultures survived the expansion of Yamna, and especially East Bell Beakers after ca. 2500 BC, which transformed Western, Northern, and Central Europe, and even East Europe reaching the modern Baltic countries, Belarus, and Romania. Even Trzciniec was born out of the influence from expanding Bell Beakers into earlier Corded Ware territory, although the later (Iron Age) relevance of this culture was probably quite limited.

As you can imagine, without horses and horse symbolism, horse riding, carts, and intensive cattle-breeding (associated with Yamna and the broad, east-central European grasslands typical of steppe regions), there can be no Proto-Indo-European, whose reconstructed vocabulary is particulary rich in horse-related words, and whose reconstructed culture, society, and religion cannot be understood without the domesticated horse. In forest regions to the north-east and eastern Europe, there was apparently little space for horses, but plenty of room for other ungulates and thus hunting, and indeed Uralic languages

In the upcoming months we will see R1a-fans associating Proto-Indo-Europeans more and more with wool, and sheep, and corded ware, and forest regions, until the proposed homeland shifts to the Baltic and Finland, instead of dat boring horse-riding people of the steppes…No wait, it’s already happening.

NOTE. Also open access is the recent Horse Y chromosome assembly displays unique evolutionary features and putative stallion fertility genes, by Janečka et al. Nature Communications (2018).

Related

Ancient DNA upends the horse family tree

New paper, behind paywall, Ancient genomes revisit the ancestry of domestic and Przewalski’s horses, by Gaunitz et al., Science (2018)

Abstract:

The Eneolithic Botai culture of the Central Asian steppes provides the earliest archaeological evidence for horse husbandry, ~5,500 ya, but the exact nature of early horse domestication remains controversial. We generated 42 ancient horse genomes, including 20 from Botai. Compared to 46 published ancient and modern horse genomes, our data indicate that Przewalski’s horses are the feral descendants of horses herded at Botai and not truly wild horses. All domestic horses dated from ~4,000 ya to present only show ~2.7% of Botai-related ancestry. This indicates that a massive genomic turnover underpins the expansion of the horse stock that gave rise to modern domesticates, which coincides with large-scale human population expansions during the Early Bronze Age.

You can read more about it in the article Ancient DNA upends the horse family tree.

Excerpts, from the article (emphasis mine):

That none of the domesticates sampled in the last ~4,000 years descend from the horses first herded at Botai entails another major implication. It suggests that during the 3rd Mill BCE at the latest, another unrelated group of horses became the source of all domestic populations that expanded thereafter. This is compatible with two scenarios. First, Botai-type horses experienced massive introgression capture (22) from a population of wild horses until the Botai ancestry was almost completely replaced. Alternatively, horses were successfully domesticated in a second domestication center and incorporated minute amounts of Botai ancestry during their expansion. We cannot identify the locus of this hypothetic center due to a temporal gap in our dataset throughout the 3rd Mill BCE. However, that the DOM2 earliest member was excavated in Hungary adds Eastern Europe to other candidates already suggested, including the Pontic-Caspian steppe (2), Eastern Anatolia (23), Iberia (24), Western Iran and the Levant (25). Notwithstanding the process underlying the genomic turnover observed, the clustering of ~4,023-3,574 year-old specimens from Russia, Romania and Georgia within DOM2 suggests that this clade already expanded throughout the steppes and Europe at the transition between the 3rd and 2nd Mill BCE, in line with the demographic expansion at ~4,500 ya recovered in mitochondrial Bayesian Skylines (fig. S14).

przewalski-botai
Admixture graphs. (A to F) The six scenarios tested. Panel (A) received decisive Bayes Factor support, as indicated below each corresponding alternative scenario tested. Domestic-Ancient and Domestic-A/B refer to three phylogenetic clusters identified within DOM2 (excluding Duk2): ancient individuals; modern Mongolian, Yakutian (including Tumeski_CGG101397) and Jeju horses, and; all remaining modern breeds. (G) Posterior distributions of admixture proportions along p1 and p2 branches.

This study shows that the horses exploited by the Botai people later became the feral PH. Early domestication most likely followed the ‘prey pathway’ whereby a hunting relationship was intensified until reaching concern for future progeny through husbandry, exploitation of milk and harnessing (7). Other horses, however, were the main source of domestic stock over the last ~4,000 years or more. Ancient human genomics (26) has revealed considerable human migrations ~5,000 ya involving “Yamnaya” culture pastoralists of the Pontic-Caspian steppe. This expansion might be associated with the genomic turnover identified in horses, especially if Botai horses were best suited to localized pastoral activity than to long distance travel and warfare. Future work must focus on identifying the main source of the domestic horse stock and investigating how the multiple human cultures managed the available genetic variation to forge the many horse types known in history.

We are seing that Bell Beakers were obviously horse riders, and that their horses must have derived from Yamna riders, so it is quite possible that their ancestral early Khvalynsk culture was the origin of domesticated horses, as proposed by David W. Anthony, although for the moment we only know “that [horse] domestication could have been a process with many phases, experiments, failures, and successes”.

EDIT (23 FEB 2018): My interpretation errors removed, thanks to the comments.

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