The first stage in the collection of brachiopods was to scan the entire exposed section for protruding brachiopods. All brachiopods detected were extracted from these unconsolidated sediments using the blade of a penknife and placed immediately in sample bags wrapped in aluminum foil to exclude light. Reducing the exposure of the coloured fossils to light is likely to be important in preserving original colour because the molecules responsible for shell colouration are known to be sensitive to both light and oxygen (Cheesman et al. 1967). The brachiopods have a patchy distribution along the section, often being clustered around the base of pebbles and boulders, as they would be in life.
Once all surface brachiopods had been collected, the fossil-bearing horizon was excavated using a variety of tools (penknife, trowel, and crowbar), and the majority of brachiopods were collected as they were exposed manually. All sediment debris from the excavations was then sieved using a mesh of 10 mm, and any remaining brachiopods or fragments of brachiopods were collected. All the shells were wet when collected, due to percolation of water through the sequence, but virtually all were in perfect condition. Only two fossils were found in a decayed state--decayed brachiopod shells become soft and very fragile, and terebratulids tend to disintegrate to produce large numbers of microscopic calcite fibres in surrounding sediments (Collins 1986). It is possible that the water-logging noticed in parts of this section is a comparatively recent development caused by the recent damming of the Wairoa Stream. This damming produced a small lake, which is used for industrial purposes.
On the evening of collection all fossils were washed of sediment and then dried between layers of tissue paper. All sample processing was carried out in subdued lighting. During washing it became clear the grey sediment infill often masked the delicate orange-red colour of the fossil terebratulid brachiopods--being very thin shelled, the dominant colouration of brachiopods with a sediment infill was grey. Once dried, the cleaned fossils were placed in sealed black tubes or photographic sample bags that excluded light for transportation back to Glasgow.
In Glasgow, the specimens were stored in plastic containers inside black plastic photographic bags, and exposure to light was minimized. Specimens were photographed uncoated using a Nikon DCS 410 digital camera, and the resulting images processed using Adobe Photoshop software™. All illustrated specimens have been deposited in the collections of the Hunterian Museum, University of Glasgow, Scotland (GLAHM).