Pachyscyllium gilberti

Pachyscyllium gilberti

(Casier, 1946)

Common name Catshark
Fossil group Sharks & Rays
Order Carcharhiniformes
Family Scyliorhinidae
Genus Pachyscyllium
Taxonomic status Accepted
Geological age Thanetian and Ypresian

Summary

Pachyscyllium gilberti was a small catshark and probably a bottom-associated predator in Palaeogene marine environments. Its ecological role was likely closer to that of modern small scyliorhinids than to the large pelagic sharks that dominate popular images of fossil shark faunas.

Its tiny grasping teeth indicate a diet of small prey. Fishes, crustaceans, worms and cephalopods are all plausible food sources, although the fossil record does not preserve direct evidence of which were most important.

The species is known chiefly from isolated teeth, making its external appearance uncertain. Its importance lies in recording the smaller predatory fauna of the early Eocene seabed and demonstrating that the shark community contained many ecological levels, not just large apex predators.

Quick Identification

Look for: a very small tooth with a tall narrow central point and usually two smaller points on each side. Fine vertical lines are concentrated around the bottom of the crown, and the root below is broad with a deep groove through the middle.

Diagnostic Features

  • Main cusp is tall, narrow and sharply pointed.
  • Usually two well-developed pairs of lateral cusplets are present, with an additional marginal cusplet occasionally developed.
  • Fine vertical folds are concentrated at the labial crown base and around the cusplets lingually rather than covering the entire crown.
  • Remaining crown surface and cutting edges are comparatively smooth and unserrated.
  • Root is broad and low, with a deep central nutritive groove dividing the main root structure.

Fossil Details

Typical size
Teeth are very small, generally only a few millimetres high.
Fossil material
Tooth
Preservation
The lateral cusplets are commonly broken and weak ornament can be polished away. Damaged examples overlap with other small scyliorhinids and should not be identified solely from the central cusp.

Similar Species

Recorded Fossil Sites

Synonyms & Previous Names

Scyliorhinus gilberti

References

  • Casier, E. (1966). Faune ichthyologique du London Clay. 496 pp.. Trustees of the British Museum (Natural History), London 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
  • Rayner, D.; Mitchell, T.; Rayner, M. (2009). London Clay Fossils of Kent and Essex. 228 pp.. Medway Fossil and Mineral Society, Rochester, Kent 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
11 August 2026 Reviewed by Sam Harris