Eternauta (named after the Argentine Science Fiction comic) is an extinct genus of Ophthalmosaurid icthyosaur that lived in Late Jurassic of Argentina. The type species is Eternauta patagonica.
Discovery and Naming[]
The holotype (MLP-PV 85-I-15–1) was discovered in the outcrops of Vaca Muerta Formation, Neuquen Province, Argentina. In 1990, it was assigned to Platypterygius without discussion or the description of its anatomy. In 1997, It was assigned to Caypullisaurus. Then, in 2025, it was redescribed as a new genus because of the different anatomy from Caypullisaurus. The generic name is named after the Argentine Science Fiction comic, The Eternaut, while the specific name is named after Patagonia. Combining the generic name and specific name results in Eternauta patagonica, meaning "The one who navigates eternally in Patagonia".
Description[]
The postorbital region is particularly distinct, and is informative in distinguishing it from Caypullisaurus. The postorbital bone is weakly developed front-to-back. the postorbital extends significantly below the orbit, and the back region of the mandible is distinct. The scleral ring preserved in the orbit is enlarged. There is no evidence that Eternauta had a squamosal bone.
Classification[]
It is classified as a member of Platypterygiinae inside the clade Ophthalmosauridae.
Paleoecology[]
It had a different feeding strategy with other ichthyosaurs that lived with it, with the jaw bone being able to snap fast, agile prey.
Gallery[]
