A re-examination of the speciesEuryapteryx geranoides(Owen) including comparisons with other emeiin moas (Aves: Dinornithiformes)

Abstract

Abstract The moa taxon Euryapteryx geranoides (Owen) is redescribed on the basis of cranial, sternal and leg bone characters. No significant differences between it and E. gravis (Owen) were found, so the synonomy of gravis with geranoides by Cracraft (1976) is supported. The minimum and maximum size limits of this species are extended but total variation is still similar to that in emeid moas, in which sexual dimorphism in size has not been demonstrated. There is a north to south increase in size, shown by leg bone length, for E. geranoides in the North Island. Although bones from South Island populations were larger than those from the North Island, a similar clinal variation over the length of the South Island cannot be demonstrated from present material. However, there is intersite size variation in the South Island that is probably related to site age. Cranial parameters were examined to see whether there was any justification for the taxon Zelornis Oliver. No supporting data were found, so the synonomy of this taxon in Euryapteryx by Cracraft is supported. The types of Euryapteryx pygmaeus Hutton were examined and found to represent an individual at the smallest end of the size range for E. geranoides. References to an undescribed species of Euryapteryxby R J. Scarlett are found to be unsupported. These references were all based upon small specimens of Emeus crassus. Therefore this study confirms that the past avifauna of New Zealand had only the 11 species of moa listed by Worthy 1988a.