Cameroceras

Cameroceras
Temporal range: Ordovician
Partial internal mold of C. inaequabile, Upper Ordovician of northern Kentucky
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: †Endocerida
Family: †Endoceratidae
Genus: †Cameroceras
Conrad, 1842
Type species
†Cameroceras trentonense
Conrad, 1842
Species

See text.

Cameroceras ("chambered horn") is an extinct genus of endocerid cephalopod which lived in equatorial oceans during the entire Ordovician period. Like other endocerids, it was an orthocone, meaning that its shell was fairly straight and pointed. It was particularly abundant and widespread in the Late Ordovician, inhabiting the shallow tropical seas in and around Laurentia, Baltica and Siberia (equivalent to modern North America, Europe, and Asia).[1]

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,[2] is estimated to have shell around 2 metres (6.6 ft) in length,[3] while that of C. rowenaense was about 70 centimetres (2.3 ft).[1] Some books and older scientific papers previously treated Cameroceras as the absolute largest nautiloid-grade cephalopod, with a shell length reaching 5.7 metres (19 ft)[4][5] or even 9.14 metres (30.0 ft).[6][4][1] More recent studies have indicated that the largest orthocone fossils do not belong to the genus Cameroceras, but rather Endoceras giganteum. Moreover, the maximum length estimate is based on a highly doubtful field observation.[5] Cameroceras and Endoceras are indistinguishable in most anatomical aspects, only differing in their shell texture.[7]

  1. ^ a b c Frey, R.C. 1995. "Middle and Upper Ordovician nautiloid cephalopods of the Cincinnati Arch region of Kentucky, Indiana, and Ohio" (PDF). Archived (PDF) from the original on 2017-05-01. Retrieved 2023-10-25. U.S. Geological Survey, p.73
  2. ^ Kröger, Björn (2013-03-27). "The cephalopods of the Boda Limestone, Late Ordovician, of Dalarna, Sweden". European Journal of Taxonomy (41): 1–110. doi:10.5852/ejt.2013.41. ISSN 2118-9773. Archived from the original on 2022-10-02. Retrieved 2023-10-25.
  3. ^ Kröger, Björn; Ebbestad, Jan Ove R. (2014). "Palaeoecology and palaeogeography of Late Ordovician (Katian–Hirnantian) cephalopods of the Boda Limestone, Siljan district, Sweden". Lethaia. 47 (1): 15–30. Bibcode:2014Letha..47...15K. doi:10.1111/let.12034. ISSN 0024-1164. Archived from the original on 2023-11-10. Retrieved 2023-10-13.
  4. ^ a b Teichert, Curt; Kummel, Bernhard (20 December 1960). "Size of Endocerid Cephalopods". Breviora. 128: 1–7. Archived from the original on 8 April 2017. Retrieved 25 October 2023.
  5. ^ a b Klug, C.; De Baets, K.; Kröger, B.; Bell, M.A.; Korn, D.; Payne, J.L. (2015). "Normal giants? Temporal and latitudinal shifts of Palaeozoic marine invertebrate gigantism and global change". Lethaia. 48 (2): 267–288. Bibcode:2015Letha..48..267K. doi:10.1111/let.12104.
  6. ^ Flower, Rousseau H. (1955). "Status of Endoceroid Classification". Journal of Paleontology. 29 (3): 329–371. ISSN 0022-3360. JSTOR 1300321.
  7. ^ Cite error: The named reference :13 was invoked but never defined (see the help page).