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Russian Lower/Middle Volgian ammonites

Russian Lower/Middle Volgian ammonites
RuMert
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RuMert
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Lower Volgian fossils in European Russia are scarce, I can't show them yet. They are from 3 ammonite zones defined by various species of  Ilowaiskya (klimovi, sokolovi and pseudoscythica).

Middle Volgian is much more widespread, it's also  divided into 3 zones, everybody here is familiar with: Dorsoplanites panderi, Virgatites virgatus and Epivirgatites nikitini.

Dorsoplanitidae family flourished during the Middle Volgian in the entire northern (boreal) area from Siberia to Greenland. As descendants of the Perishpinctidae family, dorsoplanitids retained their gigantism (30-40 cm is the normal size for many of their macroconchs). Two Dorsoplanitidae genera (Dorsoplanites and Pavlovia) dominated the 1st Middle Volgian (panderi) zone. Dorsoplanites also evolved into Lomonossovella and the latter - into Epivirgatites, the 2 genera that in turn dominated the last (nikitini) zone. The 2nd (virgatus) zone is defined by the genus Virgatites, derived from Ilowaiskya. Their characteristic feature are numerous ribs assembled in bundles.

Mid-Volgian ammonites are often massive and preserved as rough phosphorite and sandstone steinkerns. The bigger they are the less is the chance to see the inner whorls.

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