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Temporal range: ToarcianCallovian, 183–163 Ma
Steneosaurus Holzmaden.jpg
Steneosaurus bollensis, Holzmaden Germany
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Suborder: Thalattosuchia
Family: Teleosauridae
Genus: Steneosaurus
Geoffroy, 1825
  • S. baroni Newton, 1893
  • ?S. bollensis (Jaeger, 1828)
  • S. boutilieri Eudes-Deslongchamps, 1869
  • ?S. brevior Blake in Tate and Blake, 1876
  • S. edwardsi (Eudes-Deslongchamps, 1868)
  • ?S. gracilirostris Westphal, 1961
  • S. heberti Morel de Glasville, 1876
  • S. larteti (Eudes-Deslongchamps, 1868)
  • ?S. leedsi Andrews, 1909
  • ?S. megistorhynchus (Geoffrey Saint-Hilaire in Eudes-Deslongchamps, 1869)
  • S. pictaviensis Vignaud, 1998
  • S. rostromajor Geoffey Saint Hilaire, 1825 (type)

Steneosaurus is an extinct genus of teleosaurid crocodyliform from the Early Jurassic to Middle Jurassic (Toarcian to Callovian). Fossil specimens have been found in England, France, Germany, Switzerland and Morocco. The largest species, S. heberti, reached up to 5 m (16.5 ft) long, though 2.5–3.5 m was far more common.[1]

Reconstruction of Steneosaurus bollensis
Steneosaurus bollensis
Steneosaurus heberti skull


Species in this genus are traditionally classed into two skull groups: longirostrine (long, narrow jaws) and brevirostrine (short, broad jaws).


  • S. baroni: Madagascar from the Bathonian.
  • S. bollensis: Western Europe (England, France and Germany) from the Toarcian.
  • S. boutilieri: Western Europe (England, France and Switzerland) from the Bathonian.
  • S. gracilirostris: Western Europe (England) from the Toarcian.
  • S. heberti: Western Europe (France) from the Callovian.
  • S. larteti: Western Europe (England and France) from the Bathonian.
  • S. leedsi: Western Europe (England and France) from the Callovian.
  • S. megistorhynchus: (type) Western Europe (France) from the Bathonian.
  • S. pictaviensis: Western Europe (France) from the Callovian.


  • S. brevior: Western Europe (England) from the Toarcian.
  • S. edwardsi: Western Europe (England and France) from the Callovian.

Misassigned species[edit]

  • Steneosaurus obtusidens Andrews, 1909 = Lemmysuchus
  • Steneosaurus deslongchampsianus (Lennier, 1887)[2]
  • Steneosaurus bouchardi Sauvage, 1872
  • Steneosaurus megarhinus (Hulke, 1871)[3]

Evolutionary relationships[edit]

A 2005 phylogenetic analysis into the evolutionary relationships of Thalattosuchia did not support the monophyly of Steneosaurus, as the genera Machimosaurus and Teleosaurus both fell within Steneosaurus.[4] Reinforcing the paraphyly of Steneosaurus, the Callovian species "Steneosaurus" obtusidens has been recovered as the sister species of Machimosaurus in recent cladistic analyses of Thalattosuchia and renamed Lemmysuchus, while Steneosaurus bollensis was recovered in a basal position to other members of Steneosaurus sensu lato.[5][6] Given the paraphyly of Steneosaurus, Macrospondylus von Meyer, 1830 is the earliest available generic name for S. bollensis.

Niche partitioning[edit]

From the semi-aquatic Oker locality in Lower Saxony, Germany (Kimmeridgian-age) two genera of teleosaurids (Steneosaurus and Machimosaurus) are known, in addition to the neosuchian genera Goniopholis and Knoetschkesuchus.[7]

See also[edit]


  1. ^ "croco_thalattosuchia". Archived from the original on 2014-10-20. Retrieved 2014-03-02.
  2. ^
  3. ^ Foffa D, Young MT, Brusatte SL, Steel L. (2015) New specimen and revision of the late Jurassic teleosaurid 'Steneosaurus’ megarhinus. PeerJ PrePrints 3:e1351v1
  4. ^ Mueller-Töwe, I. J. (2005). "Phylogenetic relationships of the Thalattosuchia" (PDF). Zitteliana. A45: 211–213.
  5. ^ Young, M. T.; Brusatte, S. L.; De Andrade, M. B.; Desojo, J. B.; Beatty, B. L.; Steel, L.; Fernández, M. S.; Sakamoto, M.; Ruiz-Omeñaca, J. I.; Schoch, R. R. (2012). Butler, Richard J, ed. "The Cranial Osteology and Feeding Ecology of the Metriorhynchid Crocodylomorph Genera Dakosaurus and Plesiosuchus from the Late Jurassic of Europe". PLoS ONE 7 (9): e44985. doi:10.1371/journal.pone.0044985. PMC 3445579. PMID 23028723. edit
  6. ^ Martin, J. E. and Vincent, P. (2013), New remains of Machimosaurus hugii von Meyer, 1837 (Crocodilia, Thalattosuchia) from the Kimmeridgian of Germany. Fossil Record, 16: 179–196. doi:10.1002/mmng.201300009
  7. ^ Karl H-V, Gröning E, Brauckmann C, Schwarz D, Knötschke N.2006. The Late Jurassic crocodiles of the Langenberg near Oker, Lower Saxony (Germany), and description of related materials (with remarks on the history of quarrying the “Langenberg Limestone” and “Obernkirchen Sandstone”). Clausthaler Geowissenschaften 5: 59–77.

External links[edit]