Bernhard Kummel

Lower Triassic ammonoids from western Southland, New Zealand

Summary Four species of Lower Triassic (Scythian) ammonoids are recorded from Malakoff Hill, Wairaki Downs, Southland. The assemblage (Owenites cf. O. koeneni, Flemingites cf. lidacensis, Subvishnuites welteri, and Wyomingites cf. aplanatus) clearly indicates that the fauna belongs to the Meekoceras zone (approximately Mid-Scythian), The Lower Triassic (Scythian) formations of the Circum-Pacific Region are reviewed and their ammonoid faunas attributed to the zones and ages of the Scythian Stage.

New lower triassic ammonoids from New Zealand

Abstract Prosphingites coombsi n. sp. is described from disturbed beds between Kaka Point and Nugget Point, south Otago. This species sugge5ts a late Scythian (Subcolumbites Zone) age for these strata. A summary of all species previously assigned to Prosphingites is included to substantiate the conclusions regarding the age assignment.

Environmental Significance of Dwarfed Cephalopods

ABSTRACT Dwarfed and/or small cephalopods have been recorded from many parts of the geologic column. Data assembled from preliminary studies of the Cretaceous pyritic micromorph faunas of Texas and from an Upper Triassic (Norian) fauna from the Cordillera Central of northern Peru will be given. Both of these faunas contain an abundant cephalopod assemblage, mostly small in size, which are associated with other dwarfed and non-dwarfed invertebrates. Students of cephalopods are handicapped by the relative small amount of environmental data known on recent Nautilus. Some qualitative data on the environmental relationships of fossil cephalopods is known but practically no quantitative data is available. It is suggested that evolution has probably been an important factor in causing the development of some groups of small cephalopods.

Triassic-Jurassic cenoceratids from New Zealand

Summary Evolution of nautiloids during the Triassic is a culmination of trends established in the late Paleozoic. In the late Triassic, the group suffered almost complete extinction. In New Zealand, the meagre fossil nautiloid fauna is extremely important because it includes representatives of the stock which survived into the Jurassic. Cenoceras trechmanni (Kummel) from the Otamitan Stage (upper Carnian) is redescribed and figured. Lower Jurassic nautiloids, recorded for the first time in New Zealand, are represented by two indeterminate species of Cenoceras from the Aratauran Stage (Lower Lias) of Southland.