Tucked away in the northern part of the West African nation of Ghana are the remains of a mysterious culture. With no written or oral records of the people who once lived here, all that has been left behind are the intricate and beguiling terracotta figurines found buried in mounds scattered across the region. But these clay objects may have given up some of the Koma Land peoples' long lost secrets.

The sculptures are curious objects, representing both beast and human forms, some with two heads. Many of them have cavities carved into the nostrils, ears, or mouths, the function of which is still being deciphered. But one suggestion is that they were used to hold liquids, potentially for the purpose of ritual or libation. To test this, researchers decided to see if they could gather any DNA evidence from inside these holes, and so deduce what may once have been held within.

The results, published in the Journal of Archaeological Science, are both impressive and unexpected. DNA is notoriously difficult to find in objects recovered from hot, arid environments, such as the mounds on the southern edge of the Sahara in which the figurines were first discovered. After as short a period as 200 years, it is usually thought that the DNA has degraded to such as degree that it is almost impossible to sample. But amazingly the team managed to find some scraps still within the clay.

It showed that the models had once held a variety of plant-based substances. These included evidence of plantain and bananas, now ubiquitous to most of West Africa, but when these objects were made roughly between 600 and 1300 CE, the fruits were not being cultivated by the Koma Land people. Not only that, but they also found traces of pine trees, which are not known to grow anywhere in Africa except north of the Sahara.

This suggests that while little remains of the enigmatic Koma Land culture today, back when it was flourishing it had some impressive trade links that traversed not only West Africa, but even right across the largest and hottest desert in the world. It also confirms the use of the clay figurines in ritual activities, which itself shows that the Koma Land people must have once had a rich culture, now lost to the sands of time.