Mycterosuchus

Steneosaurus Temporal range: 183–163 Ma PreЄ Є O S D C P T J K Pg N Toarcian – Callovian
Steneosaurus bollensis, Holzmaden Germany
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Infraclass:	Archosauromorpha
(unranked):	Mesoeucrocodylia
Suborder:	Thalattosuchia
Family:	Teleosauridae
Genus:	Steneosaurus Geoffroy, 1825
Species
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)
Synonyms
?Macrospondylus Von Meyer, 1830 Mycterosuchus Andrews, 1913 Mystriosaurus Munster, 1834

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.

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

Longirostrine

Brevirostrine

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. 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. Given the paraphyly of Steneosaurus, Macrospondylus von Meyer, 1830 is the earliest available generic name for S. bollensis.

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.

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Wikipedia