Discosorida

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(Derivation: linked Upper Cambrian to Cambrian)
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==Derivation==
==Derivation==
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The earliest known discosorid is ''Reudemannoceras'' which comes from the lower [[Middle Ordovician]] (Whitrockian age) strata of the Champlain Valley of New York State in North America. The closest species with respect to similar features is the [[Upper Cambrian]] ''Plectronoceras''. Both have connecting rings that are expanded where not restricted as siphuncular bulbs. The problem is that there are no Plectronocerids known to have crossed into the Lower Ordovician, or any Lower Ordovician forms known to have such features.  
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The earliest known discosorid is ''Reudemannoceras'' which comes from the lower [[Middle Ordovician]] (Whitrockian age) strata of the Champlain Valley of New York State in North America. The closest species with respect to similar features is the [[Cambrian|Upper Cambrian]] ''Plectronoceras''. Both have connecting rings that are expanded where not restricted as siphuncular bulbs. The problem is that there are no Plectronocerids known to have crossed into the Lower Ordovician, or any Lower Ordovician forms known to have such features.
==Taxonomic Comment==
==Taxonomic Comment==

Revision as of 13:45, 29 November 2013

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