Alaunian

The Alaunian, also known as "Middle Norian", is a sub-age in the Upper Triassic. It is followed by the Upper Norian, also known as Sevatian.

Stage definition

It begins with the first appearance of the ammonites Drepanites rutherfordi and Cyrtopleuritis bicrenatus and with the conodont Cypridodella multidentata. The stage ends with the first appearance of the ammonites Gnomohalorites cordilleranus and Sagenites quinquepunctatus and the conodont Cypridodella bidentata.

Fossils

The holotype MPUM 6009 of the Bergamodactylus pterosaur was found in a layer of the Zorzino Limestone Formation dating from the early Norian (upper Alaunian).

See also

References
    • Additions to the uppermost Alaunian through Rhaetian (Triassic) conchostracan zonation of North America: New Mexico Museum of Natural History and Science HW Kozur, RE Weems - Bulletin, 2011


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