Are these Ammoniods?


Nov 6, 2012
Hi, old member. Haven't been here since 2014, i think. While dissolving mid Devonian limestone for microfossils i found these little white discs. One of them seems to have septa on the inside. Could these things be ammonitellas of protoconchs of goniatite ammoniods?


More like 0.5mm in size. The microscope was designed for circuits and i had to put my iPhone camera to the eyepiece (thats why the image quality is so bad).

I was looking for conodonts but found tentaculites, ostracods, chondrichthyan scales/teeth, placoderm gnathals, acanthodian scales, onychodont scale fragments, at least one good conodont, and a bunch of other things i couldn't identify.

As for macrofossils, no ammonoids but a lot nautiloids like brevicone oncocerids, a few orthocones, plus corals, stromatoporoids, brachiopods and bivalves. I call the rock layer GPF9, as it was the ninth layer I tested for microfossils in the mid Devonian Gravel Point Formation.
It looks like you are finding a lot of good stuff. I just don't see anything that points to an ammonoid or cephalopod shell...
Well, in the first photo I thought the walls within the bisected shell looked like septa and the gaps between the said septa and the borders of the shell looked like space for a siphuncle. That and the whole white objects sometimes had the shape of an ammonoid. They probably aren't, but I still can't tell what they are.

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