After Bardet, Godefroit & Sciau, 1999, O'Keefe, 2001, and Benson, Evans & Druckenmiller, 2012
<==o †Plesiosauria de Blainville, 1835 sensu O'Keefe, 2001 [Streptosauria Cope, 1869] (plesiosaurs; joutsenliskot) |-- †Pliosauroidea Welles, 1943 sensu O'Keefe, 2001 (lyhytkaulaiset joutsenliskot; pliosaurs, short-necked plesiosaurs) `--o †Plesiosauroidea (Gray, 1825) Welles, 1943 sensu O'Keefe, 2001 (pitkäkaulaiset joutsenliskot; plesiosaurs, long-necked plesiosaurs) |-- †Eoplesiosaurus antiquior Benson, Evans & Druckenmiller, 2012 `--+--o †Plesiosauridae Gray, 1825 sensu O'Keefe, 2001 | `--o †Plesiosaurus De la Beche & Conybeare, 1821 [Pentatarsostinus Hawkins, 1840] | |?- †P. macrocephalus Conybeare, in Buckland, 1836 | `-- †P. dolichodirus Conybeare, 1824 [P. macromus Owen, 1840] `--o †Euplesiosauria O'Keefe, 2001 |?- †Sthenarosaurus dawkinsi Watson, 1909 [a Rhomaleosaurid sensu Smith & Dyke, 2008] |?- †Leurospondylus ultimus Brown, 1913 |-- †Cryptoclidia Williston, 1925 sensu Ketchum & Benson, 2010 [Cryptoclidoidea Williston, 1925 sensu O'Keefe, 2001] `--+--+-- †Djupedalia engeri Knutsen, Druckenmiller & Hurum, 2012b | `--o †Spitrasaurus Knutsen, Druckenmiller & Hurum, 2012a | |-- †S. larseni Knutsen, Druckenmiller & Hurum, 2012a | `-- †S. wensaasi Knutsen, Druckenmiller & Hurum, 2012a `--o †Elasmosauridae Cope, 1869 sensu Bardet, Godefroit & Sciau, 1999 |-- †Elasmosauridae Cope, 1869 sensu O'Keefe, 2001 `?-o †Microcleididae Benson, Evans & Druckenmiller, 2012 |-- †Morenosaurus stocki Welles, 1943 |-- †Eretmosaurus rugosus (Owen, 1840) Seeley, 1874 [Plesiosaurus rugosus Owen, 1840] `--+-- †Westphaliasaurus simonsensii Schwermann & Sander, 2011 `--+-- †Seelyosaurus guilelmiimperatoris (Dames, 1895) White, 1940 [Plesiosaurus guilelmiimperatoris Dames, 1895; incl.? Seeleyosaurus holzmadensis White, 1940; Plesiosaurus tournemirensis Sciau, Crochet & Mattieu 1990] `--o †Microcleidus Watson, 1909 sensu Benson, Evans & Druckenmiller, 2012 |-- †Occitanosaurus tournemirensis (Sciau, Crochet & Mattei, 1990) Bardet, Godefroit & Sciau, 1999 [Plesiosaurus tournemirensis Sciau, Crochet & Mattieu 1990] `--o †Microcleidus Watson, 1909 |-- †M. (Hydrorion) brachypterygius von Huene, 1923 [jr. synon. of Plesiosaurus [= Seelyosaurus] guilelmiimperatoris sensu Storrs, 1997] `--o †(Microcleidus Watson, 1909) |-- †M. homalospondylus (Owen, 1865) Watson, 1909 `-- †M. macropterus (Seeley, 1865) Watson, 1911
Plesiosauria incertae sedis:
†Aptychodon Reuss, 1855 †“Plesiosaurus” ichthyspondylus †“Plesiosaurus” balticus †“Cimoliasaurus” cantabrigiensis †Discosaurus Leidy, 1852 †Dravidosaurus blanfordi Yadagiri & Ayyasami, 1979 [regarded as a stegosaur by the original descriptors] †Opallionectes andamookaensis Kear, 2006; E.Cret. Aust. †Orophosaurus Cope, 1887 †Pantosaurus Marsh, 1893 †Piptomerus Cope, 1887 [nomen dubium] †Piratosaurus Leidy, 1865 [nomen dubium]
Alternative phylogenies of basal plesiosaurs
After Carpenter, 1999 (via Ketchum & Benson, 2010)<==o †Plesiosauroidea |-- †Cryptoclididae `--+-- †Plesiosauridae `--+-- †Brancasaurus `--+-- †Microcleidus `--+?- †Mureanosaurus (sedis mutabilis) `--+-- †Leptocleidus `--o †Elasmosauridae |-- †Liponectes `--+-- †Elasmosaurus `--+-- †Styxosaurus |-- †Hydrotherosaurus |-- †Hydralmosaurus |-- †Callawayasaurus `--+-- †Thalassomedon `-- †Tuarangisaurus |
After Bardet, Godefroit & Sciau, 1999 (via Ketchum & Benson, 2010)<==o †Plesiosauroidea |-- †Hydrorion |-- †Plesiosaurus `--+-- †Seeleyosaurus `--+--o †Cryptoclididae | |-- †Tricleidus | `-- †Cryptocleidus `--o †Elasmosauridae |--+-- †Mureanosaurus | `--+-- †Microcleidus | `-- †Occitanosaurus `--+-- †Alzadasaurus `--+-- †Hydrotherosaurus `-- †Thalassomedon Reference:
|
After O'Keefe, 2001<==o †Plesiosauria |--o †Pliosauroidea | |-- †Thalassiodracon | `--+-- †Eurycleidus | |-- †Attemborosaurus | |-- †Rhomaleosauridae | `-- †Pliosauridae `--o †Plesiosauroidea |-- †Plesiosaurus `--o †Euplesiosauria O'Keefe, 2001 |-- †Microcleidus |-- †Elasmosauridae `--o †Cryptoclidoidea |-- †Cryptoclididae `--o †Tricleidia |-- †Tricleidus |-- †Cimoliasauridae [= Aristonectidae] `-- †Polycotylidae Reference:
|
After Gasparini et al, 2002 (via Ketchum & Benson, 2010)
<==o †Plesiosauroidea
|-- †Plesiosaurus
`--+-- †Mureanosaurus
`--+-- †Tricleidus
`--+-- †Vinialesaurus
`--+-- †Kimmerosaurus
`-- †Cryptocleidus
|
After Gasparini et al, 2003 (via Ketchum & Benson, 2010)<==o †Plesiosauroidea |-- †Plesiosaurus `--+--o †Cryptocleididae | |-- †Tricleidus | `-- †Cryptocleidus `--o †Elasmosauridae |-- †Microcleidus `--+-- †Mureanosaurus |-- †Occitanosaurus `--+-- †Aristonectes |-- †Hydrotherosaurus |-- †Libonectes `-- †Callawayasaurus |
After Großmann, 2007 (via Ketchum & Benson, 2010)<==o †Plesiosauroidea |-- †Thalassiodraco `--+-- †Plesiosaurus `--+--o †Cryptocleididae | |-- †Cryptocleidus | `-- †Kimmerosaurus `--o †Elasmosauridae |-- †Seeleyosaurus |-- SMNS 16812 [Plesiopterys] `--+-- †Mureanosaurus `--+--+-- †Libonectes | `-- †Bracasaurus `--+-- †Occitanosaurus `--+-- †Microcleidus `-- †Hydrorion |
After Ketchum & Benson, 2010 (fig. 6)<==o †Plesiosauria |--+-- BMNH 49202 | `--+-- †Archaeonectrus | `-- †Macroplata `--+-- †“Plesiosaurus” macrocephalus `--+-- †Attemborosaurus `--o †Neoplesiosauria Ketchum & Benson, 2010 |-- †Pliosauroidea `--o †Plesiosauroidea |-- OUMNH J.10337 `--+--+-- †Hauffiosaurus | `--+-- MMUM LL 8004 | `-- †“Macroplata” longirostris `--+-- †Thalassiodragon `--+--o Plesiosauridae | |--+-- †Plesiosaurus | | `-- †Seelyosaurus | `--+-- †Microcleidus | `--+-- †Hydrorion | `-- †Occitanosaurus `--+-- †Elasmosauridae [incl. Aristonectidae] `--o †Cryptoclidia |--o †Cryptocleididae | |--+-- †Cryptoclidus | | `-- †Kimmerosaurus | `--+-- †Mureanosaurus | `-- †Tricleidus `--o †Leptocleidia |-- †Leptocleididae `-- †Polycotylidae Reference(s):
|
After Vincent, Bardet, Pereda Suberbiola, Bouya, Amaghzaz & Meslouh, 2011:<==o †Plesiosauroidea |-- †Thalassiodraco `--+-- †Plesiosaurus `--+-- †Seeleyosaurus `--+-- †Occitanosaurus `--+--+-- †Eromangasaurus | `--+--+-- †Kaiwhekea | | `-- †Tuarangisaurus | `--+-- †Nichollssaura | `--+-- †Thililua | `-- †Dolichorhynchops `--o †Elasmosauridae |-- †Microcleidus `--+-- †Callawayasaurus `--+--+-- †Thalassomedon | `--+-- †Hydralmosaurus | `-- †Styxosaurus `--+-- †Hydrotherosaurus `--+-- †Terminonatator `--+-- †Libonectes |-- †Futabasaurus `-- †Zarafasaura Reference(s):
|
After Benson, Evans & Druckenmiller, 2012<==o †Plesiosauria |-- †Rhomaleosauridae `--o †Neoplesiosauria |-- †Pliosauridae `--o †Plesiosauroidea |-- †Eoplesiosaurus `--+-- †Plesiosaurus `--o †Euplesiosauria |--+-- †Plesiospterys | `-- †Cryptoclidoidea `--o †Microcleididae |-- †Eretmosaurus |-- †Westphaliasaurus `--+-- †Seelyosaurus `--o †Microcleidus |-- †M. (Occitanosaurus) tournemirensis `--+-- †M. (Hydrorion) brachypterygius `-- †M. (Microcleidus) homalospondylus Reference:
|
Reference(s):
- Bardet, N., Godefroit, P. & Sciau, J., 1999: A new elasmosaurid plesiosaur from the Lower Jurassic of southern France.
–Palaeontology: Vol. 42, #5, pp. 927-952 - Benson, R. B. J., Evans, M. & Druckenmiller, P. S., 2012: High Diversity, Low Disparity and Small Body Size in Plesiosaurs (Reptilia, Sauropterygia) from the Triassic–Jurassic Boundary.
–Plos One: Vol. 7, #3, pp. e31838 [doi: 10.1371/journal.pone.0031838] - Creisler, B., 1999-2001: Plesiosauria translation and pronunciation guide.
–iNet: Dinosauria.com: http://www.dinosauria.com/dml/names/ples.html - Druckenmiller, P. S. & Knutsen, E. M., 2012: Phylogenetic relationships of Upper Jurassic (Middle Volgian) plesiosaurians (Reptilia: Sauropterygia) from the Agardhfjellet Formation of central Spitsbergen, Norvay.
–Norwegian Journal of Geology: Vol. 92, pp. 277-284 - Everhart, M., 2000: Something about Plesiosaurs.
–iNet: WWW.OceansofKansas.com: http://www.oceansofkansas.com/plesio2.html - Everhart, M., 2000: Something about Pliosaurs.
–iNet: WWW.OceansofKansas.com: http://www.oceansofkansas.com/pliosaur.html - Kazlev, M. A., 1999: Attenborosaurus.
–iNet: http://www.kheper.auz.com/gaia/biosphere/vertebrates/sauropterygia/Attenborosaurus.html - Kazlev, M. A., 1999: Family Plesiosauridae.
–iNet: http://www.kheper.auz.com/gaia/biosphere/vertebrates/sauropterygia/Plesiosauridae.htm - Kazlev, M. A., 1999: Sthenarosaurus.
–iNet: http://www.kheper.auz.com/gaia/biosphere/vertebrates/sauropterygia/Sthenarosaurus.html - Kear, B. P., 2006: Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage.
–Palaeontology: Vol. 49, #4, pp. 837-856 [doi: 10.1111/j.1475-4983.2006.00569.x] - Ketchum, H. F. & Benson, R. B. J., 2010: Global interrelationships of Plesiosauria (Reptilia, Sauropterygia) and the pivotal role of taxon sampling in determining the outcome of phylogenetic analyses.
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–Norwegian Journal of Geology: Vol. 92, pp. 187-212 - Knutsen, E. M., Druckenmiller, P. S. & Hurum, J. H., 2012b: A new plesiosauroid (Reptilia: Sauropterygia) from the Agardhfjellet Formation (Middle Volgian) of central Spitsbergen, Norway.
–Norwegian Journal of Geology: Vol. 92, pp. 213-234 - Maisch, M. W. & Rücklin, M., 2000: Cranial osteology of the sauropterygian Plesiosaurus brachypterygius from the Lower Toarcian of Germany.
–Palaeontology: Vol. 43, #1, pp. 29-40 - O'Keefe, F. R., 2001: A cladistic analysis and taxonomic revision of the Plesiosauria (Reptilia: Sauropterygia).
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–Paleobiology: Vol. 28, #1, pp. 101-112 - Rieppel, O. C., 1997: Part II: Sauropterygia – Introduction. 107-119
in Callaway, J. M. & Nicholls, E. L., (eds.) 1997: Ancient Marine Reptiles.
–Academic Press, San Diego, 1997, xivi-501 - Storrs, G. W., 1997: Morphological and taxonomic clarification
of the genus Plesiosaurus. 145-190
in Callaway, J. M. & Nicholls, E. L., (eds.) 1997: Ancient Marine Reptiles.
–Academic Press, San Diego, 1997, xivi-501 - Storrs, G. W., Arkhangel'skii, M. S. & Efimov, V. R., 2000: Mezosoic marine reptiles of Russia and other former Soviet republics. 187-210
in Benton, M. J., Shishkin, M. A., Unvin, D. M. & Kurochkin, E. N., (eds.) 2000: The Age of Dinosaurs in Russia and Mongolia.
–Cambridge University Press, Cambridge, 2000, xxxix-696