My Method for Recording Breakage Patterns in Bones

My Method for Recording Breakage Patterns in Bones

            I recently have been tasked with analysing the zooarchaeological assemblage at Westward House. Myself and my tutor performed an initial assessment of the assemblage, and what immediately struck us was how consistently the bones were broken in specific places. I knew that this would be a major aspect of the assemblage, and set about looking at ways to record these breakages. To my surprise, there was little work creating a recording method to accurately say how many bones were broken in a certain way... So I created my own!

What are ‘Breakage Patterns’ and Why record them?

            Breakage patterns describe how the bone is broken, for example a humerus can be transversely split along the shaft. The breakages that are recorded are not modern damage, so they were not caused by the excavators! And they also are not gnawed of ends of butchered bits of bones, they are bones which have been broken in the past, ‘Ancient Breaks’, that may have been caused by humans or other taphonomic devices.

           

Because it is unknown what causes ancient breaks I believe it is very important to record them, to see any patterns emerging from the assemblage. For example, although I have only recorded around 300/400 bones so far from Westward House, I am already noticing patterns from the site that I would like to be able to quantify and interpret. For example longditidually split long bones are paticaularly common, which could have been due to individuals deliberately breaking them to extract marrow (See Figure 1). Another pattern I have noticed is transverse breaks through the distal and proximal shafts of metapodials (See Figure 2), although I haven’t been able to work out why this is yet, a method to record these will at least go to prove that this is far too commonly occurring to be a natural coincidence, and something strange is going with Cow feet!

Figure 1: Longitudinally Broken Long Bones from Westward House

Figure 2: One of many Transversely broken Metapodials from Westward House.

            How my Method works and How to Interpret the Results?

My method creates a three/four letter code that can be applied to any type of breakage pattern. The first one/two letters represent what element the breakage occurs on e.g. S for Scapula. The next section  is a number which represents what ‘zone’ (Area of the bone) is broken, e.g. a S1 is the glenoid cavity of a scapula. Although this might seem complicated, it is set out so a description of the zone can be read, and it follows the zonation scheme set out originally by Hambleton and Maltby, who have provided pictures to make it easy to follow!

Figure 3: An example of the coding system. Column 1 is the Elements name. Column 2 is the code to use for the element. Column 3 is a description of the zone, and Column 4 is what code to use for the zone.

The last piece of the code is to describe what the break looks like (See figure 4), which will be the last letter of the code. So S1T would be a transverse break across the glenoid cavity of a scapula.

Figure 4: Example Code for the breakage pattern type

This information can allow certain types of breakage patterns to be easily quantified in a number of ways. The simplest way is to count which is most common, e.g. 15 of H5T vs only one H1L would show a trend towards transverse breaks in distal Humerus. This can be further quantified to shows differences between phases of the site and even differences between feature types, which I will both be experimenting with at a later date. Once you have quantified it, patterns may start to appear, and once they do, how you interpret them is down to you!

I have not included the full the recording scheme due to myself continuously developing the scheme and working on it to get to a publishable state. If you are interested in using the recording scheme for your own work though, give me a shout on my email (Found in my about me section) and I will be happy to give you a copy!

Ageing Bones through Butchery Methods #1: The Iron Age

Ageing Bones through Butchery Methods #1: The Iron Age

As part of my course in Msc Osteoarchaeology, I have been researching a site called Westward House near Fishbourne. As part of this research I have been looking at identifying who occupied the site from the way they butchered animals which can be seen on the surviving animal bone. The way an animal is butchered varies from period to period. This was first recognised by Maltby (2007) who noted distinct patterns of Roman style butchery, that was unique to the period due to the appearance of specialist butchers for the first time. 

                  For this blog I have looked at the most common type of butchery found on bones from the Iron Age period. To do this I took the most detailed Iron Age butchery analysis available (Wilson 1978) and looked at whether the patterns noted, were reflected on other Iron Age sites, to create a few ‘tell-tale’ signs of an Iron Age butcher. 

Note: The following ‘signs’ have been developed for Cattle due to that being what my research at Westward House is focusing on. I haven’t tested this on other species yet! Some of these signs may also apply to other periods, however if a lot of these signs are occurring they do give a good indication that they are e.g. more likely to be Iron Age than Roman.

Sign #1: The Skull

                               The skull is commonly found in Iron Age deposits due to complete inhumations often being placed at the bottom of pits and ditches. The Iron Age hillfort of Battlesbury Bowl found a number of skulls, a number of which contained evidence of butchery. Cut marks were found around the cranium, eye socket/zygomatic and below the horn cores. This pattern was also found on skulls from Abingdon and Maiden Castle. This has been interpreted as the skinning of the skull to be used as decoration, e.g pole axed or hung.

                               Another sign to look out for on the skull is transverse cuts below the condyles of the mandible and cuts on the maxilla which were used to remove the tongue and cheek meat. This is different from the Roman period, were large cleaver marks are more commonly seen in these areas.

Sign #2: The Scapula

                               The scapula/shoulder blade is often a  focal point of butchery due to it often being used to disarticulate the upper limbs. The analysis of the Abingdon Iron Age material showed that small cut marks were common just behind the glenoid cavity in Iron Age remains. This is a pattern also seen at Maiden Castle and Battlesbury Bowl.

Figure 1: Scapula showing where the small precise cut marks were noted from the Abingdon assemblage. Wilson 1978.

     Sign #3: The Long Bones

                            

                             Long bones show a similar pattern to the scapula, with small fine cut marks being seen around the articulations of bones, for the purpose of disarticulation and meat removal. Common areas where fine knife cuts are seen are the distal Humerus (See figure 2), the Proximal Ulna and Radius (See figure 3) and proximal Metapodials. This method of butchery also appears on Iron Age animal bone assemblages such as Abingdon, Maiden Castle, Norse Road and Battlesbury Bowl. 

Figure 2: Diagram of the Distal Humerus showing where the small precise cut marks were noted from the Abingdon assemblage. Wilson 1978.

Figure 3: Diagram of the Proximal Ulna showing where the cut marks were noted from the Abingdon assemblage. Wilson 1978.

Figure 4: Diagram of Proximal Metapodials showing where the cut marks were noted from the Abingdon assemblage. Wilson 1978.

Sign #4: The Astragalus and Calcaneus

                          The final, and one of the most distinct, Iron Age butchery marks is from the Astragalus and Calcaneus bones. When the Astragalus and Calcaneus are articulated (as shown in figure 5), a large number of transverse cut marks are seen, particularly on the anterior Astragalus. This is a pattern seen on Iron Age sites such as Maiden Castle and Abingdon where they were noted as being ‘prolific’ (Wilson 1978). 

Figure 4: Diagram of the Astragalus and Calcaneus showing where the cut marks were noted from the Abingdon assemblage. Wilson 1978.

Other Iron Age butchery methods have been noted and are worth a mention such as the trimming of the vertebral column and cut marks around the articular areas of vertebrae. However the few ‘Signs’ outlined give a good indication of where typical Iron Age butchery can be seen, and shows how the analysis of butchery can be used to date a bone assemblage.

 Although it is possible that e.g. cut marks on the astragalus can be from the Roman or Medieval periods, when a large assemblage contains a lot of these signs it is likely to be Iron Age. Furthermore, another interesting aspect about Iron Age butchery is the lack of chop and cleaver marks, with small cut marks often being the only type of butchery being seen, almost being as distinctive as the signs outlined above.

Bibliography/Further Reading

Armour-Chelu, M., 1991.  The Faunal Remains.  In: Sharples, N. Maiden Castle: Excavations and Field Survey 1985-1986.  London: English Heritage Archaeological Report. 19, 139-151.

Maltby, M., 2007. Chop and Change: Specialist Cattle Carcass Processing In Roman Britain. In: Croxford, B., Ray, N., Roth, R. and White, N. (Eds.) TRAC 2006: Proceedings of the Sixteenth Annual Theoretical Roman Archaeology Conference. Oxford: Oxbow Books.

Wilson, B., 1978. Methods and Results of Bone Analysis. In: Parrington, M.,1978. The Excavation of an Iron Age Settlement, Bronze Age Ring Ditches and Roman Features at Ashville Trading Estate Abingdon. Oxfordshire: Oxfordshire Archaeological Unit Report 1.

The Westward House Project: The Aims and Objectives

The Westward House Project: The Aims and Objectives

         I have always been interested in the Iron Age/Roman transitional period in my local area of Chichester and Fishbourne, so for my Master’s degree dissertation I wanted to look at something zooarchaeological in the area. Fortunately I was presented with the opportunity to do this by Fishbourne Roman Palace, who introduced me to the site of Westward House.

         The site of Westward House is located nearby to Fishbourne Roman Palace, however the activity there pre-dates the palace itself.  The dating of the site currently relies on pottery evidence, with early imported Roman Pottery and Late Iron Age coarse pottery dating features to around AD 30. Usually this site would be interpreted as being occupied by Iron Age inhabitants, due to it predating the Roman Invasion of AD 43, however a military building found directly underneath Fishbourne Roman Palace has led to some authors to suggest that the Roman Military had settled in the area before the invasion. 

Figure 1: Site plan of Westward House (In Box) showing the nearby military granaries underneath Fishbourne Roman Palace. Allen 2011

The Roman Military remains underneath Fishbourne Roman Palace consist of timber framed buildings and ditches, interpreted by Cunliffe (1998) as granaries used by the military. The dating of the military phase at Fishbourne is poor, even though the site has the potential to pre-date the Roman Invasion. Due to the close proximity of Westward house to the military building underneath Fishbourne, it has been suggested that the two sites might be part of the same large military complex, which if that is the case, could prove that the Roman military were in Fishbourne before the Roman Invasion.

         To look at who occupied the site I am going to be looking at the animal bones from the site. To do this I plan to look at how the animal bone from the site is butchered. Iron Age and Roman butchery practices vary greatly, so from analysing these remains It should be possible to determine whether it was the Roman military or the local Iron Age population who were present in the area before the Roman Invasion.

         I aim to keep updating my blog with more information about the project as time goes on. I am aiming to complete the project by September, however I hope to write up more detailed information about the project as well. Including information about; 

- The Regini (The tribe who occupied the area)

- The difference in Roman and Iron Age butchery practices 

- Information about the site itself

- Some of the more interesting animal bones I find! (I have already found a Bear toe, which I will hopefully be writing about soon!)

References/Further Reading

Allen, M., 2011. Animalscapes and Empire: New Perspectives on the Iron Age/Romano-British Transition. Ph.D thesis. University of Nottingham.

Cunliffe, B., 1998. Fishbourne Roman Palace. Gloucestershire: Tempus Publishing Ltd.