Ctenacanthiformes Explained

Ctenacanthiformes is an extinct order of cartilaginous fish. They possessed ornamented fin spines at the front of their dorsal fins and cladodont-type dentition,[1] that is typically of a grasping morphology, though some taxa developed cutting and gouging tooth morphologies.[2] Some ctenacanths are thought to have reached sizes comparable to the great white shark, with body lengths of up to 7m (23feet) and weights of NaNkg (-2,147,483,648lb).[3] The earliest ctenacanths appeared during the Frasnian stage of the Late Devonian (~383-372 million years ago), with the group reaching their greatest diversity during the Early Carboniferous (Mississippian), and continued to exist into at least the Middle Permian (Guadalupian). Some authors have suggested members of the family Ctenacanthidae may have survived into the Cretaceous based on teeth found in deep water deposits of Valanginian age in France[4] and Austria,[5] however, other authors contend that the similarity of these teeth to Paleozoic ctenacanths is only superficial, and they likely belong to neoselachians instead.[6]

Taxonomy

Ctenacanthiformes are suggested to be more closely related to living elasmobranchs (modern sharks and rays) than to Holocephali (which includes living chimaeras).[7] The monophyly of the Ctenacanthiformes has been questioned, with some studies recovering the group as a whole as paraphyletic or polyphyletic with respect to other groups of total group elasmobranchs like Xenacanthiformes.[8]

Following Hodnett et al. 2024[9]

Ctenacanthidae Dean 1909

Heslerodidae Maisey 2010

"Saivodus group"

Notes and References

  1. Duffin. Christopher J.. Ginter. Michal. 2006. Comments on the selachian genus Cladodus Agassiz, 1843. Journal of Vertebrate Paleontology. 26. 2. 253–266. 10.1671/0272-4634(2006)26[253:COTSGC]2.0.CO;2. 86094427 .
  2. Hodnett . John-Paul M. . Elliott . David K. . Olson . Tom J. . Wittke . James H. . August 2012 . Ctenacanthiform sharks from the Permian Kaibab Formation, northern Arizona . Historical Biology . en . 24 . 4 . 381–395 . 10.1080/08912963.2012.683193 . 0891-2963.
  3. Maisey . John G. . Bronson . Allison W. . Williams . Robert R. . McKinzie . Mark . 2017-05-04 . A Pennsylvanian ‘supershark’ from Texas . Journal of Vertebrate Paleontology . en . 37 . 3 . e1325369 . 10.1080/02724634.2017.1325369 . 0272-4634.
  4. Guinot. Guillaume. Adnet. Sylvain. Cavin. Lionel. Cappetta. Henri. 2013-10-29. Cretaceous stem chondrichthyans survived the end-Permian mass extinction. Nature Communications. en. 4. 1. 2669. 10.1038/ncomms3669. 24169620. 2041-1723. free.
  5. Feichtinger. Iris. Engelbrecht. Andrea. Lukeneder. Alexander. Kriwet. Jürgen. 2020-07-02. New chondrichthyans characterised by cladodont-like tooth morphologies from the Early Cretaceous of Austria, with remarks on the microstructural diversity of enameloid. Historical Biology. en. 32. 6. 823–836. 10.1080/08912963.2018.1539971. 92392461. 0891-2963.
  6. Ivanov . A.O. . 2022-06-05 . New late Carboniferous chondrichthyans from the European Russia . Bulletin of Geosciences . 219–234 . 10.3140/bull.geosci.1845 . 1802-8225. free .
  7. Frey . Linda . Coates . Michael . Ginter . Michał . Hairapetian . Vachik . Rücklin . Martin . Jerjen . Iwan . Klug . Christian . 2019-10-09 . The early elasmobranch Phoebodus : phylogenetic relationships, ecomorphology and a new time-scale for shark evolution . Proceedings of the Royal Society B: Biological Sciences . en . 286 . 1912 . 20191336 . 10.1098/rspb.2019.1336 . 0962-8452 . 6790773 . 31575362.
  8. Luccisano . Vincent . Rambert-Natsuaki . Mizuki . Cuny . Gilles . Amiot . Romain . Pouillon . Jean-Marc . Pradel . Alan . 2021-12-02 . Phylogenetic implications of the systematic reassessment of Xenacanthiformes and 'Ctenacanthiformes' (Chondrichthyes) neurocrania from the Carboniferous–Permian Autun Basin (France) . Journal of Systematic Palaeontology . en . 19 . 23 . 1623–1642 . 10.1080/14772019.2022.2073279 . 1477-2019 . 239328598.
  9. Hodnett . John-Paul M. . Toomey . Rickard . Egli . H. Chase . Ward . Gabe . Wood . John R. . Olson . Rickard . Tolleson . Kelli . Tweet . Justin S. . Santucci . Vincent L. . February 2024 . New ctenacanth sharks (Chondrichthyes; Elasmobranchii; Ctenacanthiformes) from the Middle to Late Mississippian of Kentucky and Alabama . Journal of Vertebrate Paleontology . en . 10.1080/02724634.2023.2292599 . 0272-4634.

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