Undetermined undetermined

O’Gorman, José Patricio & Otero, Rodrigo A., 2023, Revision of the short-necked Cretaceous plesiosaurians from New Zealand, Comptes Rendus Palevol 22 (6), pp. 77-90 : 82

Elasmosauridae indet .

( Fig. 3E, F)

Polycotylidae indet . – Welles & Gregg 1971: 46.

MATERIAL. — CM Zfr 125 , a juvenile propodial .

LOCALITY AND HORIZON. — No information, probably Waipara District ( Fig. 1), according to Welles & Gregg (1971).

REMARKS

Based on propodial indices, Welles & Gregg (1971) identified this specimen as a juvenile “pliosaur” (sensu lato, following Welles 1943), noting a 90° angle between the capitulum and trochanter/tuberosity (as it is an indeterminate propodial). The presence of unexpanded distal end of the bone are features observed among juvenile. What is more these traits and the general proportions of CM Zfr 125 are remarkably similar to those described in the juvenile articulated postcranial skeleton SGO.PV.260 from the upper Maastrichtian of central Chile, referred to Aristonectes quiriquinensis ( Otero et al. 2015: fig. 4A). While CM Zfr 125 could be narrowly comparable to the latter species, the lack of additional associated skeletal remains precludes its adscription to aristonectines. This is why it is kept as an indeterminate elasmosaurid.