Palaeos Vertebrates Ichthyosauria: Thunnosauria

Palaeos Palaeos Ichthyosauria
Vertebrates Thunnosauria

Ichthyosauria: Thunnosauria

Abbreviated Dendrogram
   |   `--o Ichthyopterygia / ICHTHYOSAURIA
   |       |--Utatsusaurus
   |       `--+--Ichthyosauria
   |           `--+--Merriamosauria 
   |              `--+--Euichthyosauria
   |                 `--+--Parvipelvia
   |                    |--Eurhinosauria
   |                    `--o Thunnosauria
   |                       |--Stenopterygius
   |                       `--+--Ichthyosaurus
   |                          `--Ophthalmosauria

Ancestral Ichthyosaurs
Mixosaurs and Cymbospondyls
Shastasaurs and basal Euichthyosaurs
Temnodontosaurs and Eurhinosaurs

Taxa on this Page

  1. Ichthyosaurus X
  2. Stenopterygius X
  3. Thunnosauria X


StenopterygiusThunnosauria: Chacaicosaurus

Range: Late Triassic, but mostly Early Jurassic to middle Cretaceous

Phylogeny: Parvipelvia: Temnodontosaurus + Eurhinosauria + *: Stenopterygius + (Ichthyosaurus + Ophthalmosauria).

Characters: diapophyses & parapophyses round [S97]; diapophysis on anterior spine attaches to neural arch & moves down centrum to fuse with parapophysis in sacral vertebrae [S97]; parapophysis also moves ventrally, but not as much; caudal vertebrae with 1 articular facet [S97]; pubis & ischium rod-like [M97]. 

References: McGowan (1997) [M97]; Sander (1997) [S97].

Note: It will be disappointing if this turns out not to be a clade, since it is so aptly named.  These are, indeed, the tuna-lizards. ATW020517.

Stenopterygius: S. quadriscissus Quenstedt

Range: Early Jurassic to Middle Jurassic of Europe & South America.

Phylogeny: Thunnosauria: (Ichthyosaurus + Ophthalmosauria) + *.

Characters: to 2-3 m; generally similar to Ichthyosaurus; small head; see image for unusual structure of skull; exceptionally large orbit compared to size of head; dramatic overbite; narrow paddles (hence the name). 

Image:  fossil replica image from  Larger image and various close-ups at this site.

Links: Prehistoric World Images - Stenopterygius - Jurassic reptile; Stenopterygius; Stenopterygius quadriscissus; Weight; Biology 356 (detail of forelimb); jurassic images (another strikingly beautiful image from Doug Henderson); Dinosaurios: Stenopterygius; Fossilienverkauf (remarkable selection of photos); Gallery of fossil amphibians, reptiles and birds; Bernstein, Fossilien, Ammoniten, Repliken und vieles mehr zum Kaufen; Neuigkeiten aus der Wissenschaft; Bilder aus der Stenopterygius Fossilien-Sammlung von Armin Bauer; Ichthyosaur Stenopterygius quadriscissus (fossil image); Stenopterygius ステノプテリギウス (model); Dinowelt-Stenopterygius; Ichthyosaurier Stenopterygius quadriscissus Quenstedt - ... (fossil images); [스테노프테리기우스(Stenopterygius)] (Korean: several good images); Gallery of fossil amphibians, reptiles and birds (very nice, but tiny image); 標本解説 ステノプテリギュウス.   ATW020517.


Range: Late Triassic(!?) to Early Jurassic of Europe & North America. [C97a]

Phylogeny: Thunnosauria:: Ophthalmosauria + *.

Characters: ~2 m; jaws of equal length; maxilla relatively small [M97]; orbits enlarged [M97]; narrow posorbital region [M97]; pronounced dorsal fin; nares very close to orbits; polydactyly;  

Links: Ichthyosaurus teunuirostris (Italian); No. 973: Owen's Ichthyosaurus; The Field Museum of Natural History Ichthyosaurus; Marine Reptiles: Ichthyosaur: Ichthyosaurus; Ichthyosaure - Reptile marin de l'Ere Secondaire; Dinosaurios: Ichthyosaurus; Hawkins 1834 - Page 14 - The Ichthyosaurus Chiroligostinus (not certain this is Ichthyosaurus itself, but an incredible site all the same). 

References: Callaway (1997a) [C97a]; McGowan (1991) [M91]; McGowan (1997) [M97]. ATW020517.

checked ATW050512