Ibexian Series, Blackhillsian Stage
Zone I Cephalopods

Pictured below are a few I have seen in the informal Calathium member of the Fillmore Formation, in the southern House Range.

Endosiphocone with Calathium
Endocerid? (Endosiphocone) with Calathium

Living Chamber
External mold with filled-in siphuncle and body chamber.  Alot of trilobite parts, but no nautiloid shell...?

Coiled Cephalopod

The body chamber of an unidentified coiled nautiloid

An Endocerid?


A couple of small Orthocones surrounded with trilobite parts


a small coiled nautiloid found by Marcus Donivan

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