Baptanodon

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title: "Baptanodon" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["ophthalmosaurinae", "late-jurassic-ichthyosaurs", "jurassic-reptiles-of-north-america", "late-jurassic-extinctions", "fossil-taxa-described-in-1880", "ichthyosauromorph-genera"] description: "Extinct genus of reptiles" topic_path: "general/ophthalmosaurinae" source: "https://en.wikipedia.org/wiki/Baptanodon" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Extinct genus of reptiles ::

| fossil_range = Late Jurassic, | image = Gilmore Notes on Osteology of Baptanodon Plate XXXVI.png | image_caption = Holotype skull of B. natans | taxon = Baptanodon | authority = Marsh, 1880 | type_species = †Baptanodon natans | type_species_authority = Marsh, 1880 | synonyms =

• Ophthalmosaurus natans Marsh, 1879
• Sauranodon Marsh, 1879 (preoccupied)
• Microdontosaurus Gilmore, 1902

Baptanodon is an ichthyosaur of the Late Jurassic period (160-156 million years ago), named for its supposed lack of teeth (although teeth of this genus have since been discovered). It had a graceful 3.5 m long dolphin-shaped body, and its jaws were well adapted for catching squid. Major fossil finds of this genus have been recorded in North America. The type species, Sauranodon natans, was originally included under Sauranodon in 1879, but this name was preoccupied.

Discovery and species

Baptanodon is a replacement name for Sauranodon applied to ichthyosaur material in 1879 and was moved to its own genus Baptanodon in 1880 when Sauranodon was found to be preoccupied. Baptanodon was considered a junior synonym of Ophthalmosaurus by Maisch & Matzke (2000). However, cladistic analyses published in the 2010s indicate that Baptanodon is not congeneric with Ophthalmosaurus icenicus.

Classification

The cladogram below follows Fischer et al. 2012.

|label1=Thunnosauria |1={{clade |1=Ichthyosaurus |2={{clade |1=Stenopterygius |2={{clade |1=Chacaicosaurus |label2=Ophthalmosauridae |2={{clade |1=Arthropterygius |label2=***** |2={{clade |label1=Ophthalmosaurinae |1={{clade |1=Mollesaurus |2={{clade |1=Ophthalmosaurus |2={{clade |1=Baptanodon |2=Acamptonectes }} }} }} |label2=Platypterygiinae |2={{clade |1={{clade |1=Brachypterygius |2={{clade |1=Maiaspondylus |2={{clade |1=Aegirosaurus |2=Sveltonectes }} }} }} |2={{clade |1="Platypterygius" hercynicus |2={{clade |1=Caypullisaurus |2={{clade |1=Athabascasaurus |2="Platypterygius" australis (=Longirostria) }} }} }} }} }} }} }} }} }} }}

Palaeobiology

Fossils of Baptanodon have been found in the Oxfordian-age Sundance Formation of Wyoming, which also has yielded fossils of the cryptoclidids Tatenectes and Pantosaurus, and the pliosaurid Megalneusaurus.

References

References

1. Gilmore, C. W.. (1902). "Discovery of teeth in ''Baptanodon'', an ichthyosaurian from the Jurassic of Wyoming". Science.
2. (2014). "Palaeoecology of the marine reptiles of the Redwater Shale Member of the Sundance Formation (Jurassic) of central Wyoming, USA". Geological Magazine.
3. O. C. Marsh. 1879. A new order of extinct reptiles (Sauranodonta), from the Jurassic Formation of the Rocky Mountains. ''The American Journal of Science and Arts, series 3''
4. Maisch MW, Matzke AT. 2000. The Ichthyosauria. ''Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie)'' '''298''': 1-159.
5. (2010). "A new Lower Cretaceous (lower Albian) ichthyosaur genus from the Clearwater Formation, Alberta, Canada". Canadian Journal of Earth Sciences.
6. Valentin Fischer. (2012). "New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary". PLOS ONE.
7. Ilaria Paparella; Erin E. Maxwell; Angelo Cipriani; Scilla Roncacè; Michael W. Caldwell (2017). "The first ophthalmosaurid ichthyosaur from the Upper Jurassic of the Umbrian–Marchean Apennines (Marche, Central Italy)". ''Geological Magazine''. 154 (4): 837–858. doi:10.1017/S0016756816000455.
8. Arkhangel'sky, M. S., 1998, On the Ichthyosaurian Genus Platypterygius: Palaeontological Journal, v. 32, n. 6, p. 611-615.
9. Marsh, O. C., 1880, Note on Sauranodon: ''American Journal of Science, 3rd series'', v. 19, n. 4, p. 491.
10. Marsh, O. C., 1895, The Reptilia of the Baptanodon Beds: American ''Journal of Science, 3rd series'', v. 34., n. 299, p. 405-406.

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