In Depth
Cameroceras is widely regarded as one of if not the largest orthocone cephalopods to ever exist. Unfortunately only estimates for the upper size of the animal exist. More modern interpretations at the end of the twentieth century estimated the length of the shell at around six meters long, though estimates from earlier in the twentieth century suggested that it was as much as nine and even eleven meters long. Even at six meters long however, Cameroceras is still one of the largest cephalopods that we know about, especially for one that lived in the Ordovocian period.
Cameroceras was a cephalopod, a type of mollusc that includes the octopuses, squids and cuttlefish that we know today, and because of this we can infer a few things about the living animal. The head of the animal would have been soft muscular tissue situated at the opening of the hard cone-like shell, with the mantle (main body) lying within the shell for protection. Tentacles would have grown from the base of the head like in a modern cuttlefish, and these tentacles would have been used to seize and manipulated prey as the Cameroceras prepared to feed. 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 would have been so strong that it could crunch straight through the hard shells of other orthocones or even the hard supposedly armoured exoskeletons of eurypterids. Within the beaks of modern cephalopods a ‘toothed’ tongue is used to rasp out soft tissue from within the preys shell, though it is not known for certain if Cameroceras had this feature. In addition to eurypterids and other Ordovician cephalopods, Cameroceras may have also hunted early jawless fish.
Occasionally when Cameroceras has been shown in popular culture it has been depicted as having poor eyesight. This is mostly speculation as the eyes of Cameroceras have never been found, but it is a curious decision to suggest such a thing since most cephalopods are visually orientated predators, and some of them actually have quite exceptional eyesight. We do not know for certain how good the eyesight of Cameroceras was but other cephalopods are noted for having a great ability to pick out colours as well as gather and filter light to see in very dark water.
The history of Cameroceras as a taxon goes all the way back to 1842 at a time when the science of palaeontology was still very much in its infancy. This is why Cameroceras has also been dubbed a ‘wastebasket taxon’ because so many other large orthocone fossils have been attributed to the genus when they should not have been. Many of these specimens have since been re-labelled as belonging to other genera, however some genera of large orthocones such as Endoceras have been speculated to actually be synonyms to Cameroceras, suggesting that the fossils may actually belong after all.
Further Reading
- The Lower Silurian Cephalopoda of Minnesota. J. M. Clarke - In: E.O. Ulrich, J.M. Clarke, W.H. Scofield & N.H. Winchell The Geology of Minnesota. Vol. III, Part II, of the final report. Paleontology. Harrison & Smith, Minneapolis. pp. 761–812. - 1897. – Status of Endoceroid Classification. Journal of Paleontology 29: 329–371. - Rousseau H. Flower - 1955. - Size of Endocerid Cephalopods. Breviora Mus. Comp. Zool. 128: 1–7. - C. Teichert & B. Kummel - 1960. - Middle and Upper Ordovician nautiloid cephalopods of the Cincinnati Arch region of Kentucky, Indiana, and Ohio. - U.S. Geological Survey. - R. C. Frey - 1995.- The cephalopods of the Kullsberg Limestone Formation, Upper Ordovician, central Sweden and the effects of reef diversification on cephalopod diversity. – Journal of Systematic Palaeontology. 17 (12): 961–995. – Bj�rn Kr�ger & Martina Aubrechtov� – 2019.
