A partial ichthyosaur (?Ophthalmosauridae) skeleton from the Tithonian (Upper Jurassic) of western Cuba

Here we report the discovery of the first partially articulated ichthyosaur skeleton from the insular Caribbean. The specimen is embedded in a limestone slab that is exposed in the ceiling of a fluvial cave in El Cuajaní, within the Viñales Geopark and National Park in western Cuba. The study of the microfossil assemblages from the fossil-bearing slab indicates that the section where the specimen is embedded belongs to the Upper Tithonian El Americano Member of the Guasasa Formation. The exposed segment of the skeleton includes the U-shaped curved vertebral column with associated ribs, isolated vertebrae, and a single hindlimb. The hindlimb morphology is comparable to that of Tithonian platypterygiine ophthalmosaurids, resembling Caypullisaurus bonapartei and Aegirosaurus leptospondylus. This fossil represents the most complete ichthyosaur recovered from Cuba to date and extends the temporal record of ichthyosaurs on the island, which previously only included specimens from the Oxfordian.