Plesiosauria indet.

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 : 84

Plesiosauria indet.

( Fig. 5A, E)

Pliosauridae gen. et sp. indet . – Wiffen & Moisley 1986: 249.

MATERIAL. — NPC CD 460 , three sacral and two caudal centra, disarticulated ribs, phalanges, and fragment of pubis? ( Fig. 5 A-E).

LOCALITY AND HORIZON. — Mangahouanga Stream , a northern tributary of Te Hoe River , inland Hawke’s Bay, North Island ( Fig. 1), New Zealand. Maungataniwha Sandstone Member of the Tahora Formation. Upper Campanian-lower Maastrichtian ( Vajda & Raine 2010).

REMARKS

The vertebrae were interpreted as cervicals by Wiffen & Moisley (1986). The pubis is severely damaged and it is not possible to assess its general outline. The phalanges are not diagnostic. Therefore, the vertebral series is the most diagnostic material of this specimen. The specimen is reinterpreted here as three sacral vertebrae and two caudal centra ( Fig. 5 A-G). This interpretation is consistent with the preserved ribs as the first and second are rod-shaped, as it is usual in elasmosaurids; while the third posterior rib is dorsoventrally compressed, being similar to the caudals. Thus, the referral to Polycotylidae based on the typical short cervical centra is here discarded as they are considered sacral and caudal vertebrae.