## Diagnostic Zones

The concept of recording the diagnostic zones present for a specimen originated with Watson's work on bones from Cyprus (1979), and has been developed by various others, including Rackham (1986) and Cohen and Serjeantson (1996). This idea progressed with the publication of Dobney and Rielly's paper, 'A method for recording archaeological animal bones: the use of diagnostic zones' (1988), which was in turn the basis for the Environmental Archaeology Unit's (EAU) recording protocol (Dobney, Jaques and Johnstone 1999). For mammal and bird diagnostic zones, the York System follows the EAU protocol with minor re-coding, and most images that display the various zones originated in that report. All fish diagnostic zones are taken from Barrett's fish recording system (2001).

Diagnostic zones are recorded for many of the more commonly found elements from a variety of mammals, birds and fish. Within the York System, the relevant zone image is displayed when an element is selected on the main recording form, or when the Zone Diagram button is selected on a variety of forms.

A zone should only be recorded if more than 50% of it is present.

Depending on the speed of the computer running the application, the zone diagrams may take up to a few seconds to appear, as they are held externally to the database itself to limit file sizes. This delay is particularly noticeable for some of the larger mammal elements with many zones, such as the pelvis, femur, humerus, and radius/ulna. If a user is extremely familiar with the zone system, they may prefer to simply type in the zones that are present in each specimen.

An example of the use of diagnostic zones is illustrated on the left. In this case, the metapodial is used for recording bovid and cervid metatarsals and metacarpals. It is divided into eight different zones, each with uniquely identifiable features. As with all diagnostic zone diagrams, the user can select each zone by clicking on the relevant button, or by using the Proximal, Distal or All buttons. In addition, all diagnostic zone forms are set up to respond to keyboard input; pressing '6' will select zone 6, etc. For elements with more than 9 zones, letters are used: 'A' for the 10th zone, 'B' for the 11th, etc. This is different from the zone lettering system used in Dobney, Jaques and Johnstone. On the fish diagnostic zone forms, letters are used instead of numbers to distinguish zones. These zones can be selected by typing the relevant letters.

Once recorded, zone data can be used to calculate a variety of figures, including MNE (minimum number of elements). Two MNE reports have been included in the system.

See the list of all species and element combinations for further information on applicability of the zones system, or see the following pages for screen-shots of the various diagrams:

- Mammals
- Birds
- Fish