Facial reconstructions have become an increasingly common output of archaeological analysis. From the dark-skinned Cheddar Man (see CA 337) to the battle-scarred men from the Mary Rose, these life-like models put a face (literally) on the past in a way that artefacts cannot. Now, a reconstruction has been created from the skull of a Neolithic dog, opening up new possibilities for the ways in which this forensic technique may be used in the future. But how are these models created, and how accurate are they? In this month’s ’Science Notes‘, we explore the details of this technique and how it was applied to a canine from Orkney.
The history of facial reconstruction dates back to the 19th century, but it is only in the last three or four decades that it has become a well-established practice in both forensics and archaeology. The first step in the process is for the skull to be assessed for identifying characteristics such as sex, age, and likely ethnicity (something which is aided these days by isotopic analysis). Structural features, such as the robustness of the bone where muscles attach, the profile of the jaw, the symmetry and length of the nasal bones, and any other unusual marker, are then identified.
Once a cast of the skull has been made, the forensic artist then adds markers to specific features of the skull. These approximate the overall tissue thickness of the individual, based on averages for their sex, age, and ethnicity, and act as guidelines for the reconstruction. Next the facial muscles are added – taking into account the likely muscle mass of the individual based on the previous assessment – then the lips and nose are reconstructed. Finally, the soft tissue and skin are added, until the markers are completely covered, along with the eyes, ears, and hair.
Today, many archaeological facial reconstructions are done in combination with DNA analysis that sheds light on details such as skin pigmentation, hair colour, and eye colour. But, despite the inclusion of genetic information, there is still a degree of subjectivity involved in the process, particularly in terms of features that are not apparent based on bone structure, such as soft-tissue modifications (e.g. piercings or tattoos) or the size of the lips and nose. One of the biggest sticking points in facial reconstructions, though, is the thickness of soft tissue. As mentioned above, average thicknesses have been determined based on sex, age, and ethnicity, but there is a degree of individual variation that cannot be accounted for. This means that, while a facial reconstruction will definitely bear a resemblance to the person in life, it is unlikely to be a completely accurate likeness.
In the case of the recent canine reconstruction, this forensic technique was applied to the skull of a dog discovered in the Cuween Hill chambered cairn on Orkney. It was one of 24 found on the monument’s floor, and radiocarbon dating shows that the dogs were interred 4,500 years ago – over 500 years after the tomb was first constructed, perhaps as part of some ritual or veneration of the animal.
To create the canine model, the skull was first CT-scanned in the Diagnostic Imaging Service at Edinburgh University’s Royal (Dick) School of Veterinary Studies, and then made into a 3D-printed model by Historic Environment Scotland’s Digital Documentation team. The forensic artist Amy Thornton next used this model to build up the muscle, skin, and fur of the Neolithic animal. This proved to be a bit of a challenge. As Amy said, ‘there is much less existing data relating to average tissue depths in canine skulls compared to humans.’
Amy persevered with what information was available, however, and the result is the kindly face of man’s best friend, but with distinctly wolfish features. During the Neolithic, dog domestication was still relatively recent (see CA 301), and while dogs had already become more diminutive in size (this specimen was only the size of a large collie), it makes sense that it would have retained some of its more untamed ancestry – at least in appearance.
Commenting on the outcome, Dr Alison Sheridan, Principal Archaeological Research Curator in the Department of Scottish History and Archaeology at National Museums Scotland where the skull is curated, said: ‘We are delighted to have collaborated with HES on this very important initiative, which enables people to encounter a Neolithic dog “in the flesh”. The size of a large collie, and with features reminiscent of a European grey wolf, the Cuween dog has much to tell us, not only about ceremonial practices and the symbolic significance of the dog in late Neolithic Orkney, but also about the appearance of domestic dogs in the 3rd millennium BC.’