Did it work D? Works here.
Now, I'm wondering about how this fossil fits into the family tree.
The Paleobiology database places it in the family Rutoceratidae in the order Nautilida, but
Manda & Turek (2009) place it in family Hercoceratidae in superfamily Rutoceratoidea in order Oncocerida (so not an early nautilid).
They also write something about the spines: "Signor & Brett (1984) suggested that highly elaborated shell sculptures in nautiloids (e.g., spines, wings, collars, distinct growth walls) functioned as protection against predators and they also pointed out that increasing diversity of well-sculptured nautiloids during the Devonian represents an adaptive reaction to the radiation of durophagous predators. Appearance and diversification of rutoceratoids in the Early–Middle Devonian seems to be in agreement with these suggestions."
BUT, "It may be pointed out that rutoceratoids represent a single new Early Devonian cephalopod clade with highly sculptured shells and shell outgrowths. Remaining new Early Devonian clades exhibit clearly similar sculpture as analogous Ordovician and Devonian cephalopod morphotypes ................. Consequently, the radiation of rutoceratoids (i.e., highly sculptured cephalopods) in the Early Devonian probably represents an effect (fabricational noise) of cephalopod faunal recovery after the Silurian-Devonian boundary Event rather than a radiation of durophagous predators."
This is the first time I meet the term "fabricational noise", so browsing further I find that "it has been applied to features of morphology that contain information about the mechanism by which a structure is manufactured (Seilacher 1970, 1973,
1974)" - something about patterns "occurring in accidental or functionally neutral situations" (and I'll read
this tomorrow). I'd like to understand this better. Can anyone enlighten?