A new record of an aristonectine elasmosaurid (Sauropterygia, Plesiosauria) from the Upper Cretaceous of New Zealand, and the implications for the Mauisaurus haasti Hector, 1874 hypodigm

JOSÉ P. O'GORMAN; OTERO R.A.; HILLER. N

ALCHERINGA

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2014

0311-5518

An indeterminate aristonectine elasmosaur is recorded from a lower Maastrichtian beds of the Conway Formation, Waipara River, South Island, New Zealand. The described specimen (CM Zfr 104) previously considered part of the hypodigm of Mauisaurushaasti, came from the upper part of the Alterbidinium acutulum biozone, the same zone from which the only well-known aristonectine from New Zealand, Kaiwhekea katiki, is recorded. The cervical vertebrae of CM Zfr 104 have the same distinctive features (i.e., with extremely broad rather than long centra) as those from previously recorded juvenile aristonectines from Argentina, Chile and Antarctica. This new record is congruent with the biogeographyc relationships of the marine reptiles from the Weddellian PalaeobiogeographicProvince (i.e. Patagonia, western Antarctica, New Zealand, Tasmania and southeastern Australia). Therefore, this type of vertebra is regarded as a disctintive feature of the Weddellian aristonectine elasmosaurids.