Archaeonectrus

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title: "Archaeonectrus" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["jurassic-plesiosaurs-of-europe", "rhomaleosauridae", "fossil-taxa-described-in-1964", "sauropterygian-genera"] description: "Extinct genus of reptiles" topic_path: "general/jurassic-plesiosaurs-of-europe" source: "https://en.wikipedia.org/wiki/Archaeonectrus" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Extinct genus of reptiles ::

| fossil_range = Early Jurassic,

| image = Archaeonectrus NHM.jpg | image_caption = Holotype specimen NHMUK PV OR 38525 | taxon = Archaeonectrus | authority = Novozhilov, 1964 | type_species = Archaeonectrus rostratus | type_species_authority = Owen, 1865 Archaeonectrus is an extinct genus of pliosaur from the Early Jurassic (Sinemurian) of what is now southeastern England. The type species is Archaeonectrus (originally "Plesiosaurus") rostratus, first named by Sir Richard Owen in 1865, which was moved to its own genus by N.I. Novozhilov in 1964. It was a relatively small plesiosaur, measuring 3.4 - long. ::figure[src="https://upload.wikimedia.org/wikipedia/commons/d/d4/Archaeonectrus_rostratus_lower_jurassic_lyme_regis.jpg" caption="Additional specimen"] ::

Classification

::figure[src="https://upload.wikimedia.org/wikipedia/commons/a/a2/Archaeonectrus.jpg" caption="Illustration of the holotype specimen, NHMUK PV OR 38525 (formerly BMNH 38525), dated to {{circa}} 1870"] ::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/9/90/Archaeonectrus_NT.jpg" caption="Life restoration"] ::

The cladogram below shows Archaeonectrus phylogenetic position among other plesiosaurs, following Benson et al. (2012).

|label1=Plesiosauria |1={{clade |label1=Neoplesiosauria |1={{clade |1=Pliosauridae |2=Plesiosauroidea }} |label2=Rhomaleosauridae |2={{clade |1=Stratesaurus taylori |2={{clade |1=Macroplata tenuiceps |2={{clade |1=Avalonnectes arturi |2={{clade |1=Eurycleidus arcuatus |2={{clade |1=Meyerasaurus victor |2={{clade |1=Maresaurus coccai |2={{clade |1=Atychodracon megacephalus |2={{clade |1=Archaeonectrus rostratus |2={{clade |1=Rhomaleosaurus cramptoni |2={{clade |1=Rhomaleosaurus thorntoni |2=Rhomaleosaurus zetlandicus }} }} }} }} }} }} }} }} }} }} }} }}

References

• Sepkoski, J.J. (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology 363: 1-560.

References

1. (2010). "The anatomy and taxonomy of ''Macroplata tenuiceps'' (Sauropterygia, Plesiosauria) from the Hettangian (Lower Jurassic) of Warwickshire, United Kingdom". Journal of Vertebrate Paleontology.
2. (2020). "A new elasmosaurid plesiosaurian from the Early Cretaceous of Russia marks an early attempt at neck elongation". Zoological Journal of the Linnean Society.
3. Roger B. J. Benson. (2012). "High Diversity, Low Disparity and Small Body Size in Plesiosaurs (Reptilia, Sauropterygia) from the Triassic–Jurassic Boundary". PLOS ONE.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::