Mesopeplum waikohuense (Marwick, 1931)
MARWICK, J. 1931. The Tertiary Mollusca of the Gisborne district. New Zealand Geological Survey Paleontological Bulletin, 13: 1-177.
1931 Pallium waikohuensis Marwick 1931
«5. Mesopeplum waikohuense (Marwick, 1931): specimens from a wide range of eastem North Island Pliocene rocks agree with the types of M. waikohuense in having more numerous, narrower, more steeply folded plicae than on M. convexum (6-8 plicae, rather than the 5 of almost all M. convexum) but much fewer, coarser, more prominent, more widely spaced radial costae than on any M. convexum (only 2-3 costae on each plica is normal in M. waikohuense). Specimens of this form occur commonly with M. syagrus in eastern North Island Opoitian and Waipipian rocks, but also occur younger than any M. syagrus seen: records of Mesopeplum from Mangapanian Te Onepu Limestone in eastern North Island and from the early Nukumaruan Hautawa Shellbed in Wanganui basin are specimens more nearly resembling M. waikohuense than M. convexum. Its time range is therefore Opoitian to (about) early Nukumaruan; but the time of last appearance and the question of whether it might have evolved gradually into M. convexum are obscure as yet.»
BEU, A. G. 1995. Pliocene Limestones and their scallops. Lithostratigraphy, pectinid biostratigraphy, and paleogeography of eastern North Island late Neogene limestone. Institute of Geological & Nuclear Sciences Monograph, 10: 1-243, figs. 1-95. (New Zealand Geological Survey Paleontological Bulletin, 68). Institute of Geological and Nuclear Sciences, Ltd., Lower Hutt, New Zealand. [p. 52]
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