Ibexian Series, Stairsian Stage
Zone D Cephalopods

These cephalopods were found in the lower member of the Fillmore Formation in an algal-sponge reef deposit.  The cephalopods were deposited in the reef, then the reef was scalloped, exposing the cephalopods, then a hardground (?algal-bacterial mat) formed (the dark orange brown rind). No sign of the siphuncle is seen on most of the Orthocone specimens, so positive identification cannot be determined at this time, but they are probably Endocerids.


Aphetoceras,  a loose coiled Tarphycerid

another Aphetoceras showing the siphuncle and septa

Portion of a sponge algal reef showing a couple of unidentified Orthocones.



An Endocerid?


An Orthocone showing the body chamber and part of the phragmocone

ZoneD ortho  
an Orthocone with closely spaced septa

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