Age and provenance of Cretaceous marine reptiles from the South Island and Chatham Islands, New Zealand

Abstract

Analyses of dinoflagellate cysts from marine reptile sites in Marlborough, North Canterbury, North Otago, and on Chatham Island, indicate that the localities range from Early to latest Haumurian (Middle Campanian to Upper Maastrichtian) in age, spanning a period of c. 15 m.y. Sites in the Waipara River area are principally Upper Haumurian and range from the Alterbidinium acutulum Zone to the Manumiella druggii Zone. Sites in the Haumuri Bluff‐Ngaroma Station‐Cheviot/Jed River area are Lower Haumurian to lower Upper Haumurian and range from the Satyrodinium haumuriense Zone to the Isabelidinium pellucidum Zone. The Shag Point locality is Upper Haumurian (Alterbidinium acutulum Zone), indicating a general correlation with the Waipara localities. The Chatham Island locality is Lower Haumurian (S. haumuriense Zone), indicating a similar age to the oldest Haumuri Bluff sites. Material from two unknown sites appears to be from the Waipara River area, based on the associated dinoflagellate assemblages. Two marine reptile faunas are indicated: a Mid‐Campanian to Early Maastrichtian fauna that is replaced by a Late Maastrichtian fauna.