In a lush river valley in the Caucasus, work progressed apace on a new “early human” site in the summer of August 2021. First discovered two years ago, the finds at Orozmani, Georgia support the thesis that Homo erectus was the first hominin to reach Eurasia – and while it may have been the only hominin in town, it was not alone.
Situated on the banks of a tributary of the Mashavera River, the early Pleistocene site of Orozmani lies 120 kilometers from the Georgian capital Tbilisi and 20 kilometers from Dmanisi, home of the earliest known hominins out of Africa – Homo erectus, which reached there about 1.8 million years ago.
The story or Orozmani began in 2019 when the first survey test pit yielded early Pleistocene fossils of the saber tooth tiger Homotherium, and stone tools.
The tools were identified as belonging to the Olduwan industry, explains archaeologist Giorgi Bidzinashvili of the Georgian National Museum. The Olduwan Industry was the dominant stone tool technique used from about 2.6 million years ago until gradually being supplanted by more advanced techniques.
At Orozmani, the initial survey unearthed two Olduwan-style flakes and one hammer stone. The discoveries warranted more excavation, and so in the hot summer days of 2021 the first archaeological field season at the site took place.
The excavation was carried out mainly by the Orozmani field school with the help of enthusiastic local and international participants equipped with brushes, picks and exploration hunger. They uncovered more fossils of extinct animals from the Early Pleistocene period, next to stone tools knapped by the early hominins, Homo erectus, Bidzinashvili tells Haaretz.
Along with more fossil remains of saber tooth cats, they found bones of elephant, deer, horse, bovid, antelope, wolf, and coprolites (fossil feces) of hyenas, helping us to draw and better understand the environment that the Homo erectus encountered as they explored the Caucasus.
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The archaeologists also found more stone tools: flakes, cores, and hammer stones, all Olduwan type.
Stone tool manufacture goes back more than 3.3 million years in Africa. The first efforts produced large and crude stone artifacts, some reaching a couple of kilos in weight, predating the somewhat more sophisticated Olduwan Industry that was first described by Mary and Louis Leakey at the Olduwai Gorge in Tanzania in the 1930’ ‘s, hence the name. Further excavations in later decades until the 1970s’ uncovered more tools, which were ultimately classified into three categories: Modes I, II, and III.
The Mode I tools were “pebble tool” industries consisting of pounders, and scrapers and choppers or cores with one side left untouched while the other was knapped. This is the type of tools found at Orozmani.
New predator in town
The tools were found next to remains of extinct animal fossils, one of them being the predator Homeotherium, a saber tooth tiger that roamed the continents of Eurasia, Africa and north and south Americas from about 5 million to 28,000 years ago.
This beast weighed approximately 190 kg (420 lb) and reached 1.1 meters (3 feet 7 inches) at the shoulder.
Unlike its fellow saber toothed friends like Smilodon or Megantereon, his upper canines were shorter but were not less deadly.
Homeotherium was likely a social predator, scholars suggest. But separate work suggests that Homo erectus was a devoted carnivore, and became a new player in town competing with the cat in its territory for the meat resources.
Were the animal remains are the result of early hunting, or scavenged and brought to the site, or processed where they were found? Further research might illuminate this topic.
While no hominin fossils per se have been found at Orozmani, at least yet, next door in Dmanisi, they very much were. Five skulls and a wealth of post-cranial bones found from the early 1990s were dubbed Homo erectus georgicus: a hominin with some archaic characteristics on the one hand and other more modern features resembling those of Homo erectus.
The remains were dated back to approximately 1.8 million years ago and remain the oldest known evidence of hominins outside Africa.
The Dmanisi hominins were of individuals of different ages and even one old toothless adult, which the archaeologists interpret as an indication of early social behavior: it most likely required the help of his fellow mates in chewing food for him. (In Iraq, archaeologists discovered the remains of Neanderthals in poor condition who would also have needed help.)
But while there is no hominin remains in Orozmani, the evidence of hominin activity is clear – and helped date the arrival of early humans to Eurasia more precisely.
Orozmani’s major contributions include its dating and information that can help us recreate the paleo-environment Homo erectus encountered upon its arrival in the Caucasus.
In a paper published in 2011 by a collaboration of French and Georgian scholars, Erwan Messager, S. Nomade, Pierre Voinchet, R. Ferring, Ana Mgeladze, Herve Guillou, and David Lordkipanidze on the Kveno Orozmani geological sequence, the scientists were able to fine-tune the dating and the paleo-environmental reconstruction.
Kvemo Orozmani and Dmanisi lie on the same Mashavara lava flow basalts, which have been dated back to 1.83 million years ago. But the importance of Orozmani is that it was also covered by Orozmani basalts that didn’t reach Dmanisi, enabling us to date more precisely the two sites and their occupation to between 1.83 - 1.77 million years ago.
Using siliceous plant remains in the sediments known as phytoliths, the team could reconstruct the climate and environment these pioneers faced. When the Erectuses first ventured into the lower Caucasus, the climate was warm and humid. But as time passed, it became drier and colder, as previously was suggested based on the Dmanisi finds.
And thus, as the climate was growing less clement around 1.77 million years ago, Homo georgicus found itself competing over resources with other predators such as the Homotherium and hyenas. It is true that their ancestors had also had to cope with such huge and fierce predators in Africa too, but at least in Pleistocene-era Georgia, they didn’t risk competition from other early humans as well.