- Oxford scientists decoded ancient biodiversity from a Nimrud brick dating back to King Ashurnasirpal II’s reign nearly 2,900 years ago.
- The unburned, sun-dried brick’s preserved DNA revealed a rich tapestry of plant species, offering a unique glimpse into Assyria’s ecological past.
- This groundbreaking method, utilizing archaeological clay artifacts, could revolutionize our understanding of historical flora and fauna from diverse eras and regions.
In the shadow of the Tigris River, within the remnants of the historic city of Kalhu, now recognized as Nimrud, a simple clay brick once meant for a new palace for King Ashurnasirpal II (ca. 883-859 B.C.) has revealed more than anyone could have imagined.
A Living Time Capsule
This seemingly ordinary artifact, nearly 2,900 years old, turned out to be a unique time capsule. Hidden within were fragments of ancient DNA, which modern science has now used to shed light on the diverse flora that thrived in this region during that era.
According to a recent study published in Nature Scientific Reports, a team from Oxford University successfully extracted ancient DNA from this brick, offering unprecedented insights into the plant species cultivated in that region and period. The findings not only enlighten us about the past but also set a precedent for future research on similar artifacts from various historical eras and locations.
Decoding the Ancient Blueprint
Held in the National Museum of Denmark, the brick and its five sample points are known to have originated from the palace of the Neo-Assyrian king Ashurnasirpal II in Kalhu. The brick bears a cuneiform inscription in the now-extinct Semitic Akkadian language, denoting its association with the palace of Ashurnasirpal, king of Assyria. This crucial detail allows researchers to precisely date the artifact between 879 BC and 869 BC.
During a 2020 digitization endeavor at the Museum, researchers managed to retrieve inner core samples from the brick, ensuring minimal risk of DNA contamination. Adapting a protocol typically used for porous materials like bone, they extracted DNA from these samples.
The DNA sequencing revealed 34 unique taxonomic plant groups. Dominant among these were the Brassicaceae (cauliflower) and Ericaceae (heather) families, accompanied by others like Betulaceae (birch), Lauraceae (laurels), Selineae (umbellifers), and Triticeae (cultivated grasses). The interdisciplinary team, comprising Assyriologists, archaeologists, biologists, and geneticists, cross-referenced these findings with modern botanical records from Iraq and ancient Assyrian plant descriptions.
The Brick’s Tale
The brick, primarily composed of clay from the nearby Tigris River, was mixed with straw or animal dung before being shaped and inscribed. Rather than being baked, it was sun-dried, a process that likely helped in preserving the embedded genetic material.
Sophie Lund Rasmussen, from the Wildlife Conservation Research Unit at the University of Oxford, expressed her astonishment: “We were absolutely amazed to discover that ancient DNA, effectively protected from contamination within a mass of clay, can be successfully extracted from a 2,900-year-old brick. This research project is a perfect example of the importance of interdisciplinary collaboration in science, as the diverse expertise included in this study provided a holistic approach to the investigation of this material and the results it produced.”
Beyond the immediate findings, this research underscores the potential of utilizing clay materials, ubiquitous in archaeological sites worldwide, as rich sources of historical data. These materials can often be dated with impressive accuracy, offering glimpses into the biodiversity of ancient times.
While the current study focused on plant DNA, the methodology could potentially be expanded to identify other organisms, including both vertebrates and invertebrates.
A Glimpse into Ancient Biodiversity
The capacity to accurately depict ancient biodiversity is invaluable. It can enhance our comprehension of current biodiversity losses and deepen our understanding of past civilizations.
Troels Arbøll, a junior research fellow at the University of Oxford, emphasized the significance of the brick’s inscription: “Because of the inscription on the brick, we can assign the clay to a relatively specific time in a particular region, which means it serves as a biodiversity time capsule of information about a single site and its surroundings. In this case, it provides researchers with unique access to the ancient Assyrians.”
The groundbreaking research was a collaborative effort involving Anne Haslund Hansen of the National Museum of Denmark; Nadieh de Jonge, Cino Pertoldi, and Jeppe Lund Nielsen from Aalborg University; and the team at Aalborg Zoo.