Maxwell, P.A. 1988 Late Miocene deep-water Mollusca from the Stillwater Mudstone at Greymouth, Westland, New Zealand : paleoecology and systematics. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey paleontological bulletin 55 120 p.
Abstract: A total of 87 species of bivalves (23), gastropods (61) and scaphopods(3) are recorded from two localities of Waiauan (early Late Miocene) age near the top of the Stillwater mudstone at Karoro, near Greymouth, Westland. These faunules have little in common with other Waiauan molluscan faunules, most of which apparently lived in shallow waters, but they more closely resemble certain other Miocene assemblages of probable bathyal facies from Gisborne and Wairarapa districts. A genus-by-genus analysis of the Karoro faunules indicates an upper - but not uppermost - bathyal environment, probably in the range 400-800 m. Application of Hickman's ''taxonomic structure'' analysis to the Karoro faunules gives somewhat equivocal support to this conclusion. A critique of taxonomic structure analysis is presented; it is concluded that factors other than depth can have an important effect on the structure of molluscan faunules and consequently, considerable caution is needed when analysing fossil assemblages by this approach. A trophic analysis of the Karoro faunules shows that they are dominated by carnivores (particularly predators) and deposit feeders, whereas suspension feeders are poorly represented. Data on trophic types are used to construct an incomplete food web for the Karoro faunules. In the taxonomic section, 2 new genera are proposed and 37 new species are named. 10 revised generic classifications are suggested for New Zealand. A total of 52 new combinations are proposed. (auth.)
