St Lawrence girl reconstruction
Medieval St Lawrence girl reconstructed
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Introduction
This article reports the results of a digital forensic facial reconstruction on the skull of a young woman which was excavated from St Lawrence church in Jersey, on 30 April 2018.
The skeletal material was examined and estimations were made for sex, age at death and ancestry. The skull was then prepared for a digital forensic artist to interpret the position of the soft tissues of the face and create an image of the young woman.
In early 2018, work was begun at St Lawrence church to construct an extension on the west end of the north aisle. The extension was to house an entrance area and lavatory and planning permission was granted under the condition that an archaeological watching brief would be carried out to supervise the works.
The majority of the archaeology recorded was within the footprint of the extension in the cemetery outside the church, but a small area on the inside of the north aisle’s western end was excavated to accommodate the drainage and service pipes to the new extension.
Within this area, four burials were exposed. The bones were recorded in situ and the material within the trench was excavated. Parts of the skeletons that lay outside the footprint were left in situ, as it is not standard practice to ‘chase’ burials outside the area of excavation.
The southernmost skeleton was designated the code SK43, and the head and shoulders of this individual were removed from the trench.
The complete skull, mandible, teeth, atlas, axis, the other five cervical vertebrae, five thoracic vertebrae, one sternebra, both clavicles, the left scapula, both coracoid epiphyses, left humeral epiphysis, eight ribs, one left proximal hand phalanx and epiphysis, and the left lunate were taken for post—excavation processing and examination.
The exceptional preservation of the skull and facial bones made SK43 an ideal individual on which to carry out a forensic facial reconstruction.
Examining the osteological and archaeological evidence, it was determined that SK43 was a 15-year-old female of Caucasian ancestry, who had a moderate nutritional deficiency and some dental wear. It was not possible to ascertain the cause of her death.
Dating the Burial
Documentary evidence shows that property was sold to finance construction of the north aisle in1546 (McCormack 1986, 226).
As with other Jersey churches, the interior would have been likely to have closed for burials in the early 19th Century (Le Quesne 2014). This gives a window of just under 300 years in which SK43 could have been buried. Osteological evidence suggests SK43 lived during the earliest part of this estimation, with her burial taking place shortly after the north aisle was built.
The teeth show an accelerated rate of wear associated with the Medieval diet of bread made with stone-ground flour (Daniell 1997, 129). This bread would have tiny pieces of grit baked into it from the grinding mill stones.
Biting and chewing this gritty bread caused the incisal edges and occluding surfaces of the teeth to wear away very quickly. Despite only being a teenager, SK43 was already markedly showing this kind of damage to all of her teeth.
Sex estimation
The osteological analysis and photography were carried out on display for the public at La Hougue Bie Museum over a week in July 2019. In the absence of pelvic bones, sex was estimated using 25 sexually dimorphic features on the skull
During the pubertal growth phase in sub-adults, the skull of males and females develop differently.
This is related to the longer growth period in males, which results in an overall increase in mass and more developed muscle attachments.
In males, changes include the increased robusticity of the brow region, temporal lines and nuchal crest, and a lengthening of the face.
In females, the shorter growth period results in the retention of more sub-adult features, such as smaller size and more rounded shape, with a vertical frontal region and prominent eminences (Mays and Cox 2000).
SK43 was estimated to be female.
Ancestry estimation
The following discriminant function method for estimating ancestry was developed by Ubelaker (1999) and uses a statistical procedure to distinguish between two or more possible ancestry groups by analysing characteristics of the skull and facial bones, including projection, profile and.
As with all osteological models, the method is population specific, in this case to groups of people with European Caucasian, African Black and Native American ancestries.
This model has been used to make an ancestry estimation for SK43 in the absence of a specific Medieval Channel Island ancestry model.
Once the discriminant functions are applied to the cranial dimension measurements, a total which falls below the section point for either Black or Native American ancestry is considered to indicate the individual was Caucasian.
Age estimation
Assessing the stages of dental development provides the best evidence for age-at-death estimations in younger individuals.
When SK43 was excavated, most of her teeth were in situ, but several teeth had become loose and displaced over time. These were all recovered by sieving the soil around the top end of her grave fill.
SK43 had fully erupted adult dentition, apart from her third molars, also known as wisdom teeth. These four teeth develop within the bone of the maxilla and mandible and erupt into the mouth, if there is sufficient space, between the ages of 17-21 years old (Hillson 1996).
SK43’S third molars were unerupted, and dental x-rays confirmed that three had failed to form at all (agenesis), and only the upper left third molar was present in its dentigerous cyst within the maxilla.
On x-ray, the crown was formed to the cemento—enamel junction, but the root had not yet bifurcated. The apices of the adjacent tooth, the upper left second permanent molar, had not yet closed. This gave SK43 a developmental age of 15 years (AlQahtani 2009).
The right clavicle was recovered intact and measured at 122.04mm,
giving a developmental age range of 14-15 years old (Black and Scheuer
1996).
The measurement range for this age group is 113.3—123.5mm, with a mean maximum length of 118.5mm. This places SK43 towards the older end of the age bracket and together with the dental development estimation provides a strong indication that SK43 was 15 years old at the time of her death.
Tissue depth markers
Small, cylindrical markers were used to represent the depth of soft tissues that would have overlain the bone structure of the skull. These were cut to varying thicknesses, following Rhine and Moore’s (1984) model of tissue thicknesses based on measurement data derived from an American Caucasian population with European origins . The tissue thicknesses for a slim female individual was used, as SK43 showed a condition called cribra orbitalia in both eye sockets.
This is a reaction to a type of anaemia caused by a lack of vitamins B12 and C due to a lack of animal products in the diet, such as meat, fish, eggs and dairy, or when a rapid loss of nutrition occurs through severe gastro-intestinal infection, such as dysentery.
The body reacts to increase red blood cell production by building up more bone marrow tissue. In the eye sockets, the thin surface bone layer is perforated by the swelling bone marrow.
Photographs
Once the markers were applied, the skull was photographed in the frontal and lateral aspects, with the Frankfurt horizontal plane parallel to the floor.
A colour scale was aligned with the borders of the orbits (frontal) and the midline (lateral), and the camera, a Nikon D5200 with a 105mm macro lens, was set at a distance of 6 feet, to avoid any lens distortion.
A background setting was photographed to include in the finished image of the original stonework on north side of St Lawrence church’s north aisle exterior, with a 50cm scale.
The grey colour of the modern mortar was digitally altered to look like a lighter shade of Medieval shelly mortar, commonly used as pointing on Jersey churches at the time SK43 was alive.
It was decided to style SK43 as an average Late Medieval - Early post- Medieval Jersey parishioner, as although she was buried in the floor of the north aisle, technically a more ‘holy’ and therefore higher status burial location than the cemetery outside, her position at the very back of the church, together with the osteological evidence of her lack of access to good nutrition, indicated the she was more likely to be an average status person.
Simple dress
A simple round-neck wool dress in a natural light brown colour was chosen for her clothing.
Her hair is long and the top half is pinned back behind her ears and the rest left loose.
She is wearing no jewellery and has no other personal items, as she was found with none. This is standard in the Christian burial tradition.
Her hair and eye colour, both light brown, were selected using the average colouring for people in the Channel Island region using an online map database of European population genetics (eurpedia.com).
Digital forensic artist
The digital photographs of the skull, the background setting and selections for her colouring and appearance were sent to Tim Widden, a digital forensic artist, in London.
The soft tissues that make up our facial features relate directly to the bony landmarks of the skull beneath, therefore analysis of the skull allows an estimation of a person’s appearance in life to be produced.
The facial reconstruction of SK43 was produced as a digital composite image in which sections of real facial photographs were manipulated and blended together in PhotoShop.
The image was built over a photograph of the skull, which acted as a guide for the placement of features. The techniques for estimating the shape and position of the facial features were taken from Krogman and Iscan 1986, Taylor 2001, Premkumar 2011, Gerasimov 1955 and Balueva et al 2009.
Eyes
The process of producing SK43’s facial reconstruction started with the placement of the eyes. The iris was positioned centrally within the orbit.
The average adult eyeball is approximately 25mm in diameter, but due to SK43’s estimated age of 15 years, her eyeball diameter was estimated to be slightly smaller at 24mm.
The placement of the eye corners was informed by the points on the orbit where the palpebral ligaments secure the eyelids to the bone.
The form of the upper eyelids and eyebrows were estimated by comparing the form of the upper borders of the orbits that mirror their shape.
Nose
Female noses are almost completely fully formed by the age of 15, therefore SK43’s nose was treated as an adult’s. The shape of the lateral borders of the nasal aperture was used to inform the shape of the nose itself.
The lower border of the nasal aperture was used to indicate the form of the nostrils. The aperture is approximately three fifths the maximum width of the nose and was used to position the lateral borders of the nostrils.
The form of SK43’s mouth was estimated in relation to her teeth. The corners of the mouth were positioned at a point radiating out from between the canines and first premolars.
The line between the lips was positioned slightly above the lower edge of the upper central incisors. Due to SK43’s relatively large teeth and 6mm overjet, it was estimated that her lips would have appeared full.
The form of the ears was developed in relation to the protrusion of the mastoid processes, the bony mass behind each ear. The lower borders of the earlobes were positioned in line with the lower borders of the mastoid processes.
With the main facial features in place, the soft tissues of the forehead, cheeks and chin were added. Visual markers were added to the image to indicate the position of key muscles and were used along with the tissue depth markers to indicate the subject’s face shape.
Conclusion
The production of the facial reconstruction of SK43 was supported by the excellent condition of the skull.
While it is to be expected that some details of any facial reconstruction may be inaccurate, the preservation of the skull landmarks in SK43 facilitated the process of Visualising and placing the facial features.
Some features cannot be ascertained from the skull. Details such as hair, eye and skin colour were speculative predictions based on SK43’s ancestry estimation.
Other features such as the subject’s skin tone and condition were informed by evidence regarding her poor nutritional status.
However, the most important factor in facial recognition is the proportional configuration of the facial features (Bruce et al, 1991). Therefore a good degree of congruence can be expected between the image and the subject as she appeared in life.
Discussion
SK43 is part of a collection of 54 skeletons that were excavated from St Lawrence in 2018 that together form an invaluable population cross-section record of Medieval Jersey.
The facial reconstruction of SK43 for age and sex diagnoses of adds another very dlfferent element to the overall research value of this collection. The ability to come face to face with a Medieval islander connects the past population to the present on a very human level and brings to life the historical environment that surrounds us in a way that archaeological data and artefacts cannot. Her portrait is also a stark reminder of the hardships faced by Medieval populations and the much shorter life expectancy of people who lived under constant environmental and physical stresses, when death was a much closer part of life than we would think of It today.
According to the Medieval Christian tradition, ideas of judgment, heaven, hell and purgatory were central to the beliefs of the time and these ideas dominated the everyday culture in art, music and literature.
The very purpose of living was to prepare for the afterlife, and to be remembered and prayed for by those who are still living. Seeing her face in this way allows another generation of people living centuries later to remember this young woman and mourn her loss.
