Frances Walton ’26
Editor-in-Chief
Over the summer, at a small excavation site in the Republic of Georgia, Juliette Zúñiga ’28 discovered a fragment of a 1.8-million-year-old jawbone belonging to an early species of human.
“We only had a few hours left there, and I was working on this pile of bones that were all deposited very close to each other,” Zúñiga said. “I scraped off the edge of this block of sediment, and I saw one tooth, and I could tell it was a tooth because it’s shinier because of the enamel, and it just kind of looks like a molar. But I didn’t know it was human at first.”
Zúñiga researched in Georgia for about a month at the University of Tbilisi’s Orozmani dig site, a rural area located approximately 60 miles from Tbilisi, Georgia’s capital.
“We would stay in the village in a host’s house with a bunch of people, and the only international students there were me, two other Americans, and one student from Denmark,” Zúñiga said.
The team worked at the excavation site from approximately 9 a.m. to 4 p.m. for around three weeks before Zúñiga discovered the jawbone. Excavation was a slow, cautious process, given the bones’ fragility.
“Digging was pretty hard work because it’s hot … The site did have a roof-ish, but it’s still exposed,” Zúñiga said. “You’re bent over a lot on your knees in the dirt. And it’s very fine work, because the bones, depending on what layer they’re in and where they are situated, are in pretty bad condition and very easy to break.”
Researchers at the Orozmani site typically encounter bones in large, indistinct clusters containing various animal bones, possibly deposited at the site by a river. According to Archaeology News, a single tooth found in 2022 was the first hominin fossil found at the site. At the nearby Dmanisi site, researchers found five hominin skulls in the 1990s and early 2000s.
With only three days left in their excavation project, Zúñiga believed they would not find any hominin fossils during her time there.
“We assumed the singular tooth was a one-off, maybe because we didn’t have any luck otherwise,” Zúñiga explained. “I didn’t have high hopes we would find anything at that point because all we had found were animal bones, which are also valuable, but not what we were there looking for.”
When she first uncovered the tooth, Zúñiga thought it was a cow or other animal tooth, given the jumble of bones within the sediment.
“Then I called one of the head archaeologists over to look at it,” Zúñiga said. “He looked at it. He got very quiet, and I could tell that he thought it was something important.”
After the head archaeologist continued to expose the tooth, they became more certain that it was a hominin fossil, encased within sediment and concretions. The excavation required extreme care, using a circular saw very slowly to prevent damage to the bones from vibrations.
“Even though the teeth themselves were in very good condition, which was very lucky, the bone of the jaw was falling apart and very fragile, and the sediment that it was in was very fragile, and it was surrounded by other bones,” Zúñiga recalled. “We ended up staying until 12:30 at night trying to get it out, because we couldn’t leave it there … once we know it’s there, you need to get it out, otherwise, anything could happen overnight.”
Zúñiga’s discovery added necessary evidence to the body of scientific research surrounding the migratory patterns and population morphology of early hominins. Given the classification debates surrounding the Dmanisi skulls, which are each quite distinct from one another, even one new hominin fossil increases their sample size and available data.
“I believe right now it’s in Paris, being tested in a lab, because they have to date it,” noted Zúñiga. “They’re trying to find out if this site, or specifically, if this jaw, is older than the stuff at Dmanisi.”
Zúñiga left Georgia a couple of days later, and scientists continue to study the jawbone. At the Orozmani site, scientists also found additional tools, animal fossils, and evidence of early hominin life. Regardless of the evolving scientific classification of the Georgian fossils, Zúñiga’s summer research ultimately yielded scientific success and a new connection to our ancestors from very, very long ago.
“It’s a very deep, meaningful thing to find and to be the first person to see the jaw in 1.8 million years,” Zúñiga said.
Photo Courtesy of Juliette Zúñiga ’28
