A group of researchers has successfully isolated ancient DNA from a clay brick that is 2,900 years old, taken from the palace of Neo-Assyrian King Ashurnasirpal II. This unprecedented discovery uncovers the variety of plant species that were cultivated during that time and may pave the way for similar worldwide studies on clay materials, thus shedding light on historical biodiversity.
Currently, the National Museum of Denmark houses a clay brick from the palace of the Neo-Assyrian king Ashurnasirpal II, found in the archaic city of Kalhu. Presently known as the North-West Palace in Nimrud, it is located in modern-day northern Iraq. The foundation of this palace was set around 879 BCE. The brick bears a cuneiform inscription in the extinct Semitic language, Akkadian, which states: ‘The property of the palace of Ashurnasirpal, king of Assyria.’ This writing enables an accurate dating of the brick between 879 BCE and 869 BCE.
As part of a digitalization project in 2020 at the Museum, the researchers managed to extract samples from the brick’s inner core. The low risk of DNA contamination is attributed to the time of the brick’s creation. They then obtained the DNA from these samples using a method previously applied to other porous materials, such as bone.
The National Museum of Denmark’s clay brick, from which the samples were taken. Credit: Arnold Mikkelsen and Jens Lauridsen.
Upon sequencing the extracted DNA, 34 separate taxonomic groups of plants were identified by the researchers. The most commonly found sequences were from the plant families Brassicaceae (cabbage) and Ericaceae (heather), with other families like Betulaceae (birch), Lauraceae (laurels), Selineae (umbellifers), and Triticeae (cultivated grasses) also represented.
The interdisciplinary team, consisting of assyriologists, archaeologists, biologists, and geneticists, compared their discoveries with present-day botanical records from Iraq and ancient Assyrian plant documents.
The brick’s primary composition would have been mud from the nearby Tigris River, mixed with materials such as chaff, straw, or animal dung. Shaped in a mold and inscribed with cuneiform writing, it was left to dry in the sun. The brick was not burned but dried naturally, a process that likely helped preserve the genetic material within the clay.
Dr. Sophie Lund Rasmussen (Wildlife Conservation Research Unit, Department of Biology, University of Oxford), one of the paper’s first authors, remarked: “The successful extraction of ancient DNA from a 2,900-year-old clay brick was an exhilarating discovery. This research project exemplifies the significance of interdisciplinary collaboration in science, with the diverse expertise contributing to a comprehensive examination of the material and the insights gained.”
Dr. Sophie Lund Rasmussen at the excavation site. Credit: Sophie Lund Rasmussen.
Beyond the individual brick’s intriguing revelations, the research serves as a model for a method that could be applied to various clay archaeological sources globally, to uncover historical flora and fauna. Clay materials are often found in archaeological sites, and their context often permits accurate dating.
Though the study focused solely on plant DNA, depending on the sample, other taxa could potentially be identified, including vertebrates and invertebrates. The ability to deliver precise descriptions of ancient biodiversity could be an instrumental tool to assess current biodiversity loss and delve into the understanding of ancient and vanished civilizations.
Dr. Troels Arbøll, the study’s joint first author and junior research fellow at the Faculty of Asian and Middle Eastern Studies, University of Oxford, stated: “The inscription on the brick allows us to link the clay to a relatively specific period in a certain region, serving as a biodiversity time-capsule related to a single site and its environment. In this instance, it grants researchers exceptional insight into the ancient Assyrians.”
Reference: “Revealing the secrets of a 2900-year-old clay brick, discovering a time capsule of ancient DNA” by Troels Pank Arbøll, Sophie Lund Rasmussen, Nadieh de Jonge, Anne Haslund Hansen, Cino Pertoldi and Jeppe Lund Nielsen, 22 August 2023, Scientific Reports.
DOI: 10.1038/s41598-023-38191-w
Table of Contents
Frequently Asked Questions (FAQs) about ancient DNA extraction
What was the main discovery in the research on the 2,900-year-old clay brick?
Researchers successfully extracted ancient DNA from a 2,900-year-old clay brick from the palace of Neo-Assyrian king Ashurnasirpal II, revealing 34 distinct taxonomic groups of plants. This discovery provides insight into the diversity of plant species cultivated at that time and suggests a new method for studying historical biodiversity through clay materials.
Where is the clay brick located, and where was it originally found?
The clay brick is housed in the National Museum of Denmark and originally came from the palace of the Neo-Assyrian king Ashurnasirpal II, situated in the ancient city of Kalhu, now recognized as the North-West Palace in Nimrud, located in what is today northern Iraq.
How was the ancient DNA extracted from the clay brick?
During a digitalization project at the Museum in 2020, researchers obtained samples from the inner core of the brick, ensuring a low risk of DNA contamination. They then extracted DNA from the samples using a protocol previously applied to other porous materials such as bone.
What were the identified plant species in the extracted DNA?
The researchers identified 34 distinct taxonomic groups of plants, including families like Brassicaceae (cabbage), Ericaceae (heather), Betulaceae (birch), Lauraceae (laurels), Selineae (umbellifers), and Triticeae (cultivated grasses).
Why is this discovery significant for future archaeological studies?
The successful extraction of ancient DNA from a clay brick not only reveals information about historical biodiversity but also serves as a proof of concept. This method could be applied to many other archaeological sources of clay from different places and time periods around the world, offering a tool to better understand past flora and fauna, and potentially uncovering information about vertebrates and invertebrates.
Who were the main contributors to this research project?
The interdisciplinary team included assyriologists, archaeologists, biologists, geneticists, and researchers like Dr. Sophie Lund Rasmussen and Dr. Troels Arbøll. The collaborative effort allowed a holistic approach to the study of the material, providing valuable insights.
More about ancient DNA extraction
- Scientific Reports
- National Museum of Denmark
- University of Oxford – Department of Biology
- Wildlife Conservation Research Unit
4 comments
This is great but what else can they find, like animals or something? I mean plants are cool but what about the bigger stuff. More research needed!
I never thought a clay brick from a palace would be so important. can’t wait to see what else they’ll find out with this method.
A 2,900-year-old brick, thats unbelievable! The interdisciplinary approach is so important in these studies. Can see how history and science can go hand in hand.
Wow, just think about the biodiversity back then and what we can learn from it. this could change how we look at historical research and archaeology.