Ophthalmothule Temporal range: Tithonian-Berriasian ~145 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Quarry map (A) and reconstruction (B) of holotype skeleton
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	†Sauropterygia
Order:	†Plesiosauria
Family:	†Cryptoclididae
Genus:	†Ophthalmothule Roberts et al., 2020
Type species
†Ophthalmothule cryostea Roberts et al., 2020

Ophthalmothule (meaning "eye of the north"), was a cryptoclidid plesiosaur dating to the latest Volgian (around the Jurassic-Cretaceous boundary), found in the Slottsmøya Member Lagerstätte of the Agardhfjellet Formation in Spitsbergen. The type species is O. cryostea.^[1]

Description

Opthalmothule was a medium-sized plesiosaur, measuring 5–5.5 metres (16–18 ft) long. It was noted to have unusually large eye sockets, which suggests a paleobiological specialization, such as deep water and/or nocturnal hunting. Along with Abyssosaurus, it is one of the youngest cryptoclidids known from boreal regions. The holotype is known from skeletal material that includes a complete cranium and a partial mandible, a complete and articulated cervical vertebrae, a set of pectoral and anterior to middle dorsal series, and the pectoral girdle and anterior humeri.^[1]