Trisha Shetty (Editor)

Stephanoceras

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Kingdom
  
Superfamily
  
Stephanocerataceae

Phylum
  
Order
  
Suborder
  
Rank
  
Genus

Subclass
  
Ammonites

Stephanoceras wwwfossilmallcomPangaeapammosam11Stephanocer

Similar
  
Ammonites, Reineckeia, Tragophylloceras, Schloenbachia, Stephanoceras humphriesianum

Stephanoceras (meaning crown horn) is an extinct genus of Stephanoceratacean ammonite which lived during the Bajocian (Middle Jurassic). It is the type genus of the family Stephanoceratidae.

Contents

Stephanoceras Stephanoceras

Selected species

  • Stephanoceras blagdeni (Sowerby)
  • Stephanoceras boulderense Imlay 1982
  • Stephanoceras humphriesianum Sowery 1825)
  • Stephanoceras quenstedti Đšoche 1939
  • Stephanoceras skidegatense Whiteaves 1876
  • Description

    Stephanoceras Stephanoceras Ammonite Pos amp Neg Block

    Stephanoceras has an evolute shell, as characteristic of the family, with well-developed ribbing and tubercles. The shell is coiled so whorls barely touch in most, but some have notable overlap. Primary ribs emerge from the umbilical seam, the line marking the inner edge of the particular exposed whorl, and divide on the flanks, usually in two, occasionally in three, forming secondary ribs that cross the outer rim of the shell, known as the venter, uninterrupted. Turbercles, elevated projections, form at the ends of the primary ribs where they bifurcate or sometimes trifurcate.

    Stephanoceras Stephanoceras Stephanoceras mutabile QUENSTEDT 1886 Members

    Stephanoceras grew to be fairly large with a shell diameter as much as 27cm and width as much as 6cm across the outer whorl. Like many ammonites, Stephanoceras is dimorphic with a large, macroconch, form thought to be female and a small, microconch, form thought to be male. In most aspects the microconch is simply a smaller version of the macroconch. The primary difference lies in the aperture, which in the microconch has planar extensions on either side, lappets. That of the macroconch is generally simple, preceded by a constriction.

    Distribution

    Fossils of Stephanoceras are found in the Jurassic marine strata of Canada, Mexico, Saudi Arabia and Spain.

    Stephanoceras Stephanoceras Stephanoceras humphresianum Sowerby 1825 Members

    Stephanoceras Stephanoceras Stephanoceras humphresianum Sowerby 1825 Members

    References

    Stephanoceras Wikipedia


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