Size Cameroceras exhibited a broad range of sizes, and some species were fairly large by extinct cephalopod standards. One species,
C. turrisoides from the
Boda Limestone of
Sweden, is estimated to have shell around in length, while that of
C. rowenaense was about .
Cameroceras and
Endoceras are indistinguishable in most anatomical aspects, only differing in their shell texture. The position of the
siphuncle varies, but in most species it runs close to the lower edge of the shell. In some species, the siphuncle is voluminous, reaching a diameter equal to half of the shell diameter. The siphuncle is filled with stacked funnel-shaped concretions known as endocones, which have a simple conical form in
Cameroceras. A thin endosiphuncular tube passes through the apex of each endocone, in the lower part of the siphuncle. The surface of the siphuncle is supported by
septal necks, which are holochoanitic, meaning that they fully sheath the siphuncle and extend all the way between each septum. The main difference between
Cameroceras and
Endoceras is that
Cameroceras lacks annulations (thin concentric rings) on the outer surface of the shell. From comparison with living cephalopods, particularly the shelled
nautilus, some inferences about the biology of
Cameroceras can be made. The head of the animal would have been soft, muscular tissue situated at the opening of the shell, with the
mantle (sheath-like body wall) lying within the shell for protection. Tentacles would have grown from the base of the head, and these tentacles would have been used to seize and manipulate prey. At the base of these tentacles within the buccal mass (analogous to the mouth), a hard keratinous beak would have bitten into the bodies of its prey, and is assumed to have been strong enough to breach the prey's exoskeleton or shell. Modern cephalopods' beaks contain a
radula, or 'toothed' tongue, which is used to rasp out soft tissue from within the prey's shell. ==Classification==