Hildoceras semipolitum, Jurassic, FRA

Beautiful typical ammonite for the Toarc, delivered in a Jousi box, as pictured.Age: Jurassic, ToarcianLocality: Causses Le Clapier ,FranceSize: approx. 1,5 - 2 cmThe genus name Mercaticeras derives from Michele Mercati (a Tuscan physician who lived in the 16th century, superintendent of the Vatican Botanical Gardens) and ceras = horn, therefore the genus name means horn of Mercati. Mercaticeras shows a subquadratic section, sometimes wider than high. The shell is averagely evolute, with a spiral that grows more rapidly in the internal whirls. It is adorned by sturdy, clavate, simple ribs. The suture is simple.These ammonites lived in the Jurassic, Middle Toarcian age, Bifrons Zone to lower Variabilis/Gradatus Zone (age range: 182.0 to 175.6 million years ago).The species is called: Mercaticeras umbilicatum.The colors in the photos may differ slightly from the original for technical reasons.

Beautiful typical ammonite for the Toarc, delivered in a Jousi box, as pictured.Age: Jurassic, ToarcianLocality: Causses Le Clapier ,FranceSize: approx. 1,5 - 2 cmThe species Pleydellia aalensis is an index fossil that plays an important role in Swiss lithostratigraphy. It is known for being used to name various species that have been found in the Pleydellian Bank. This species is part of the ammonite genus and is closely linked to the Toarcian geological period.The colors in the photos may differ slightly from the original for technical reasons.