Sculpting belemnites for a museum exhibition - your thoughts are welcome

[Sordes]

Nice to see you like it. I suppose the next project wonīt be a cephalopod, but I will surely make ammonites for the museum too.

[Architeuthoceras]

Very nice sculpture Sordes!

I can't wait to see the ammonites.

[Sordes]

It seems the next models will be yet already ammonites. I have now some casts of ammonite shells which I will reconstruct and use them as basis for the soft-tissue parts.

[Terri]

Cool! This will be fun to watch.

[Sordes]

Itīs actually really not that easy to get a good cast of an undamaged ammonite. The museum has probably literally tons of ammonites in its archives, but most of them are damaged to some degree, still partly within rocks, or flattened. I have now two casts, which are in comparably good condition, but there is still a lot to restore before I can start with the soft-parts. I choose one which has one side which needs very little restoration, and when it is attached to a wall, it doesnīt matter if the other - not visible side - is somewhat damaged. One problem with ammonites is that many species have highly ornamented shells. This is hard to sculpt and also hard to restore on a fossils, for this reason I searched for a specimen with a comparably even surface.

[DWhatley]

I know Kevin will be interested in seeing your rendition of the head, arms and tentacles.

[Sordes]

It is really highly frustrating how little we actually know about ammonites, despite the fact they are among the most abundant (non-micro) fossils. There are fantastic fossils with soft tissue impressions of belemnites, but there is nothing comparable from ammonites even from the same strata. Some of the ammonites are fossilized in really perfect condition, the only thing missing are soft tissue impressions. But even this absence of structures, gives us some clues. We can for example be quite sure that ammonites had no chitinous hooks like those of belemnites, as they fossilize comparably easy. Itīs also not that probably that there were any suckers with chitinous parts. So there remains suckers, cilia or a surface similar to nautilus tentacles. I am still not completely sure how I will sculpt them. I donīt really like sucker-idea, at most I could imagine tiny sucker pads as those of Spirula. Vampyroteuthis-like cilia would be also a good choice I think. There is also not the slightest indicatpion of a beak in nautiloids, even in the best preserved fossils no chitinous beak is present, despite the fact that beaks are known from many other cephalopods like belemnites, nautilus and "modern" squids. Many reconstructions show nautiloids with beaks, even my own old models, but I wonīt sculpt a beak in the newer models. There are several indications that ammonites were planctivorous, or at least mainly predators of very small prey. For this reason I will give them also a big "umbrella" between its tentacles, similar to those of Vampyroteuthis. As a planctivore doesnīt need super-strong senses, I will also sculpt the eyes comparably small.
And last but not least I still donīt know what to do with this stupid Aptychus!

[Architeuthoceras]

I know Kevin will be interested in seeing your rendition of the head, arms and tentacles.

I was more interested in how the shell could be sculpted, not thinking of just making a mold.

And last but not least I still donīt know what to do with this stupid Aptychus!

Internal aptychi are invisible. Used as a crushing plate for plankton. I like the idea of an umbrella and small eyes.

[Sordes]

Actually the left side of the casted ammonite shell was still covered with stone (and now of course gypsum) to a big degree, and it had also some deffects. So I had to fill the deffects and carve a complete new spiral, what worked surprisingly good, my carved side looks now not much badder than the original side. I will soon post some photos. Stupidly I have no photos of the original shape.

I am not that sure that aptychi were used for grinding food, even internal ones. Why evolving an aptychus which is larger than a normal beak when prey is mainly plancton? A radula should already be able to scrunch this small animals.