And Age-Related Changes in an Iron Age Horse Skeleton from Danebury Hillfort, Hampshire
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Archaeofauna 16 (2007): 73-84 Work- and age-related changes in an Iron Age horse skeleton from Danebury hillfort, Hampshire ROBIN BENDREY Department of Archaeology, Faculty of Social Sciences, University of Winchester, West Hill, Winchester, Hampshire, SO22 4NR, UK. e-mail: [email protected] (Received November 4, 2005; Revised April 20, 2007; Accepted May 22, 2007) ABSTRACT: Pathological changes and other alterations in an Iron Age horse skeleton from Danebury, Hampshire, England are described and used to interpret the possible use of the ani- mal. The low level of pathology present in what is a relatively old animal (c.16-18 years of age at death) suggests that the horse was not heavily used, perhaps employed to pull a light cart or chariot or occasional riding. The presence of a horizontal fissure in the caudal epiphysis of the thoracic vertebra 14 may indicate that it was used for riding, possibly with either a pad saddle or bareback. KEYWORDS: HORSE, PALAEOPATHOLOGY, IRON AGE, DANEBURY, RIDING, TRACTION RESUMEN: El trabajo aborda los cambios patológicos y otro tipo de alteraciones detectados en un esqueleto de caballo de la Edad del Hierro recuperado en Danebury, Hampshire, Inglaterra y utiliza ello para interpretar los posibles usos del animal. El limitado grado de patología exis- tente en lo que parece ser un animal bastante viejo (entre 16-18 años de edad) sugiere que el caballo no fue utilizado de forma intensiva siendo su misión, posiblemente, la de tirar de un carro o carroza ligera o, incluso, ser montado de forma ocasional. La presencia de una fisura horizontal en la epífisis caudal de la vértebra torácica nº 14 podría indicar que se utilizó para la monta bien a pelo o con silla de montar. PALABRAS CLAVE: CABALLO, PALEOPATOLOGÍA, EDAD DEL HIERRO, DANEBU- RY, MONTA, TRACCIÓN 74 R. BENDREY INTRODUCTION anterior corner (Levine et al., 2002: 69 and figure 17; Benecke & von den Driesch, 2003: 79; Olsen, This article describes pathological changes and 2003: 101). Qualitative changes to the occlusal other alterations in a horse skeleton from Daneb- surface can also be used as supportive evidence for ury, an Iron Age hillfort in Hampshire, England bitting (e.g. Albarella et al., 1997: 43; Olsen, 2006: (Cunliffe, 2003). The skeleton under study derives 254-255), but the use of a bevel measurement from pit 562 (context 3) and is dated to the middle alone as evidence for bitting without comparing phase of activity at the site, c.310-270 BC (Cun- the lower second premolar (P2) against the occlud- liffe, 2003). The site produced a range of animal ing lower second premolar (P2) is insecure (Ben- bone deposits from disused grain storage pits drey, forthcoming). interpreted as evidence for ritual behaviour, of The bevel measurement method cannot be used which this skeleton is one such example (Grant, on the Danebury horse, due to the absence of the 1984). Other classes of specially deposited mater- upper dentition and the problems set out above. In ial identified at Danebury consist of groups of addition, there are no macroscopic qualitative pots, iron implements, horse and vehicle trap- changes, such as the absence or reduction of the pings, layers of burnt grain and human remains (Cunliffe, 2003). «Greaves’ Effect», the natural process whereby the softer dentine is worn down faster than the harder enamel, leaving raised enamel ridges on the occlusal surface (contact with a metal bit causes THE SKELETON both the enamel and dentine to wear down to a similar level) (see Olsen, 2006: 254-255). There is, The skeleton is that of an adult male horse, however, evidence for bitting damage to the lower based on the presence of well-developed canines second premolars (P2s) in the form of a band of and the shape of the pelvis (Sisson & Grossman, enamel exposed on the anterior edge of each tooth 1966). Analysis of lower incisor wear indicates an (Figure 1). Bendrey (in press) argues that such age of around 16 to 18 years at death (Cornevin & bands of enamel exposure on the ‘front’, or anteri- Lesbre, 1894). The cranium of the animal is miss- or, edge of equid lower second premolars derive ing. There is an empty bag in the storage boxes from a bit coming into contact with the front edge containing the skeleton labelled as containing the of the tooth and wearing away a strip of cementum cranium, and it is assumed that this part has been to expose the enamel beneath (more severe bitting removed post-excavation and that the skeleton was damage can also expose areas of dentine). Not all originally complete. enamel exposure on the anterior border of P2s can be considered as evidence for bitting, as this is a relatively exposed site and other forms of damage The mandible can occur. Bendrey (in press) suggests that to interpret such enamel exposure on the anterior For the past forty years, research into bit wear edge of P2s as evidence for bitting damage the fol- in horses –to identify that animals were bitted– has lowing criteria must be met: the height of this focussed on changes causing bevelling on the exposure should be in excess of 5mm (measured from the occlusal surface towards the mandible); lower second premolar (P2) anterior corner (e.g. Bökönyi, 1968; Clutton-Brock, 1974). Bit wear anterior exposure must not be similar to, or less analyses were developed and refined by Anthony than, any exposure on the lingual or buccal sides; and Brown (Anthony & Brown, 1991, 1989, 2003; the form of exposure should be an approximately Brown & Anthony, 1998). They define bit wear as parallel-sided band. All these criteria are met for the damage that occurs on the occlusal surface of the specimens from pit 562, for which the height the second premolars when a horse chews the bit, of the anterior enamel exposure (measured from and developed a macroscopic methodology for the occlusal surface towards the mandible) is 6.8 recording the presence of bevelling on the lower mm for the left LP2 and 9.9mm for the right. The second premolars (Brown & Anthony, 1998). This presence of bitting damage on the P2s indicates method has been criticised, as abnormal occlusion that the animal was harnessed with a bit, and was with the upper tooth can cause a bevel on the P2 therefore used for either riding or driving. Archaeofauna 16 (2007): 73-84 WORK- AND AGE-RELATED CHANGES IN AN IRON AGE HORSE SKELETON... 75 The hip and shoulder There is slight lipping of the rim of the left and right acetabuli. Although shoulder and hip injuries may be characteristic of traction (Levine et al., 2000), the slight changes observed to the acetabu- li are not strong evidence for traction compared to, for example, the eburnation that is sometimes seen in cattle acetabuli (e.g. Groot, 2005), and may be related to other factors, such as age. Indeed, com- parable changes have been observed by the author on Przewalski’s horse skeletons [in the National Museum, Prague; the collection studied in Ben- drey (2007)] that have not been worked. The fore-limbs Bony changes in the fore-limbs are restricted to the lower leg bones (the metacarpals and phalanges). New bone deposition has bridged the interosseus border between metacarpal iii and the medial and lateral accessory metacarpals in the right fore-limb FIGURE 1 (Figure 2); as it has between the metacarpal iii and Anterior view of left lower second premolar (P ) exhibiting 2 the medial accessory metacarpals in the left fore- anterior enamel exposure suggestive of bitting damage (above), with annotated drawing (below) [see Bendrey (in press) for dis- limb (the other metapodials in this horse remain cussion of bitting damage]. unattached). The ossification of the interosseous lig- FIGURE 2 Proliferative new bone formation has bridged the interosseus border between the right metacarpal ii and metacarpal iii (lateral view). Archaeofauna 16 (2007): 73-84 76 R. BENDREY aments between the metapodials in horses, a condi- The hind-limbs tion known as splints, occurs as a response to the repeated movements of the bones, causing damage Beyond the slight remodelling of the acetabuli to the connecting ligaments and periosteum of the noted above, changes in the hind-limbs are also bones, ultimately leading to their ossification recorded to the hock joints. In the left hind-limb the (Bertone, 2002). Splints is known to be, in part, age- central, third, and first and second tarsals are anky- related, and that in the metacarpals fusion progress- losed; and in the right the central and third tarsal es normally with ageing, although as stated it may are ankylosed and there is also some new bone for- also be the result of bone disease (Bertone, 2002). mation on the fourth, and first and second tarsals. The expression of the ossification of the interosseous ligaments in this animal is consistent with the pattern The articular surfaces are unaffected, and there is identified in a population of unworked Pzrewalski’s deposition of osteophytes around the articulations horses (Bendrey, 2007). The bony change is known of the tarsals and the proximal metatarsals (Figure to manifest itself earlier in the fore-limbs and the 4). This is a case of bone spavin [see Sullins (2002) medial accessory metapodials. for discussion of different forms of spavin]. The anterior proximal phalanges exhibit bilat- Bone spavin is an osteoarthritis and periostitis eral osteophytosis of the distal abaxial borders in that involves the distal intertarsal, tarsometatarsal, the insertion of the collateral ligaments of the and occasionally the proximal intertarsal joints interphalangeal joint (Figure 3). The identification (Sullins, 2002: 931). A number of possible, proba- of these lesions in the fossil equid record indicates bly inter-related, causes of spavin include heredi- that this is a naturally occurring condition (Roo- tary factors that affect conformation, severe con- ney, 1997).