Ancylocerida

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m (Ancylocerataceae: some wikilinks)
(Turrilitaceae: added Turrilitaceae)
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== Turrilitaceae ==
== Turrilitaceae ==
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The Turrilitaceae is a collection of mostly Upper Cretaceous aberrant derived Lytocerids which are commonly coiled in a helix or become uncoiled, or both; exhibiting almost every known heteromorphic form.
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The Turrilitaceae has its roots in the Lower Cretaceous Macrocephalitidae, derived from the Lytoceratidae late in the Hauterivian, which gave rise to the ancestral Hammitidae near the end of the Upper Aptian. Starting off with the Hammitidae, that gave rise to the Anisoceratidae late in the Early Albian, to the Turrilitidae at the start of the Middle Albian, and to the Baculitidae near the end of Late Albian. The Baculitidae reached into the Late Maastrichtian but  left no descendants. The Anisoceratodae gave rise to the Phycticrioceratidae of the Coniacian, but died out before. It is however the Turrilitidae and its descenent families, the Nostroceratidae, and Diplomoceratidae that dominate the clade.
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The Turritlitdae gave rise to the Nostroceratidae late in the Cenomanian.  The Nostroceratidae in tern gave rise to the Diplomoceratidae near the end of the Turonian.  The Turrilitidae range from the Middle Albian only to the Turonian but the Nostroceratidae reached the end of the Cretaceous (upper Maastricht), the Diplomiceratidae almost.
== Scaphitaceae ==
== Scaphitaceae ==

Revision as of 16:40, 12 August 2010

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