Elasmodus hunteri

Elasmodus hunteri

Egerton, 1843

Common name Chimaeroid
Fossil group Sharks & Rays
Order Chimaeriformes
Family Callorhynchidae
Genus Elasmodus
Taxonomic status Accepted
Geological age Thanetian and Ypresian

Summary

Elasmodus hunteri was a specialised Palaeogene chimaeroid, one of the cartilaginous fishes related to living chimaeras rather than a shark or ray. It possessed persistent dental plates instead of rows of replaceable teeth. Heavy plates with organised tritor tissues formed a powerful crushing and shearing feeding apparatus.

This construction suggests a bottom-associated animal able to process resistant food, probably including hard-bodied invertebrates. Its exact diet is not directly known, and details of its body and movement have to be inferred cautiously from related chimaeroids. It belonged to a long-lived radiation of specialised chimaeroids that persisted from the Cretaceous into the Palaeogene.

Quick Identification

Look for: a robust chimaeroid tooth plate containing organised elongated or lamellar tritors rather than separate tooth crowns. Palatine, mandibular and vomerine plates have different tritor arrangements, so compare like with like. Small tritor bearing chips without sufficient plate margin should remain Elasmodus sp. or Chimaeriformes.

Diagnostic Features

  • Palatine plates are massive and normally carry four to five distinct tritors.
  • Lateral palatine tritor is elongate and composed of lamellar dentine.
  • Mandibular mesial tritor is short rostrocaudally and lies parallel to the symphyseal edge.
  • Posterior outer mandibular tritor may divide into several short columns.
  • Vomerine tritors are subrectangular and associated with a limited series of outer lamellar tritors.

Fossil Details

Typical size
Centimetre scale tooth plates; dimensions vary strongly with plate position, growth stage and completeness.
Fossil material
Tooth Plate
Preservation
Tooth plates frequently break into tritor bearing fragments. An isolated tritor or plate chip may retain distinctive chimaeroid tissue but lack enough surrounding plate to establish anatomical position. Species identification should therefore be based on a sufficiently complete tritor arrangement rather than a single isolated fragment.

Similar Species

Recorded Fossil Sites

Synonyms & Previous Names

Elasmodus hunterii

References

  • Averianov, A.O. (2001). Systematics of the Cretaceous–Paleogene Chimaeroid Fish of the Genus Elasmodus (Chondrichthyes, Holocephali). Paleontological Journal, 35(3), 289–300 View reference
  • Dineley, D. & Metcalf, S. (1999). Fossil Fishes of Great Britain. Geological Conservation Review Series, 675 pp.. Joint Nature Conservation Committee, Peterborough View reference
  • Jambura, P.L.; Solonin, S.V.; Cooper, S.L.A.; Mychko, E.V.; Arkhangelsky, M.S.; Türtscher, J.; Amadori, M.; Stumpf, S.; Vodorezov, A.V.; Kriwet, J. (2024). Fossil marine vertebrates (Chondrichthyes, Actinopterygii, Reptilia) from the Upper Cretaceous of Akkermanovka (Orenburg Oblast, Southern Urals, Russia). Cretaceous Research, 155, 105779. Elsevier View reference
  • Ward, D.J. (1973). The English Palaeogene Chimaeroid fishes. Proceedings of the Geologists' Association, 84(3), 315–330 View reference
  • Ward, D.J. (1978). The Lower London Tertiary (Palaeocene) succession of Herne Bay, Kent. Report of the Institute of Geological Sciences. Institute of Geological Sciences View reference
  • Ward, D.J. (1980). The distribution of sharks, rays and chimaeroids in the English Palaeogene. Tertiary Research, 3(1), 13–19 View reference
Last Reviewed
2 September 2026 Reviewed by Sam Harris