Seeleyosaurus

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Seeleyosaurus
Temporal range: Early Jurassic, Toarcian
Cast of Seeleyosaurus guilelmiimperatoris fossil with reconstructed parts based on the holotype
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Sauropterygia
Order: Plesiosauria
Family: Microcleididae
Genus: Seeleyosaurus
White, 1940
Type species
Seeleyosaurus guilelmiimperatoris
(Dames, 1895)
Synonyms
  • Plesiosaurus guilelmiimperatoris Dames, 1895
  • Seeleyosaurus holzmadensis White, 1940

Seeleyosaurus is an extinct genus of plesiosaur that was initially placed within the genus Plesiosaurus in 1895[1] and was given its own genus in 1940.[2] Two species were known: the type, S. guilelmiimperatoris, and the now obsolete species S. holzmadensis,[2] which has since been absorbed into S. guilelmiimperatoris. It was a relatively small plesiosaur, measuring 2.9–3.6 m (9.5–11.8 ft) long.[3][4] The holotype is MB.R.1992, a large almost complete skeleton from the Upper Lias (Toarcian) Lias Group Formations of Württemberg, Germany. There seems to be the impression of a rhomboidal flap of skin in a vertical plane; if so, many plesiosaurs may have been equipped in this way.[5] A second specimen (SMNS 12039), preserved in 3D, is the holotype of S. holzmadensis.[2]

Classification

The following cladogram follows an analysis by Ketchum & Benson, 2011.[5]

 
Pistosauria
 

"Pistosaurus postcranium"

Augustasaurus hagdorni

Bobosaurus forojuliensis

Pistosaurus

Yunguisaurus liae

 
Plesiosauria
 
 Pliosauroidea 
 Pliosauridae 

Thalassiodracon hawkinsii

Hauffiosaurus spp.

Attenborosaurus conybeari

advanced pliosaurids

 Rhomaleosauridae 

Anningasaura lymense

advanced rhomaleosaurids

"Plesiosaurus" macrocephalus

Archaeonectrus rostratus

Macroplata tenuiceps

 Plesiosauroidea 

Stratesaurus taylori

 Plesiosauridae 

Seeleyosaurus guilelmiimperatoris

OUMNH J.28585

Plesiosaurus dolichodeirus

Elasmosauridae and Cryptoclidia

Microcleidus homalospondylus

Hydrorion brachypterygius

Occitanosaurus tournemiensis

Gallery

See also

References

  1. ^ a b Dames, H. W. (1895). Die Plesiosaurier der süddeutschen Liasformation. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin 2:1-83
  2. ^ a b c White, T. E. (1940). Holotype of Plesiosaurus longirostris Blake and classification of the plesiosaurs. Journal of Paleontology 14(5):451-467
  3. S2CID 84743241
    .
  4. ^ a b Ketchum, Hillary F.; Benson, Roger B.J. (2011). "A new pliosaurid (Sauropterygia, Plesiosauria) from the Oxford Clay Formation (Middle Jurassic, Callovian) of England: evidence for a gracile, longirostrine grade of Early-Middle Jurassic pliosaurids". Special Papers in Palaeontology. 86: 109–129.