Xanthilites bowerbanki

Xanthilites bowerbanki

Bell, 1858

Common name Crab
Fossil group Crustaceans
Order Decapoda
Family Tumidocarcinidae
Genus Xanthilites
Taxonomic status Accepted
Geological age Ypresian

Representative Specimens

Selected reference specimens illustrating this species from different geological units and fossil sites.

Identification Examples

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Summary

Xanthilites bowerbanki was a robust true crab that lived on the seabed of the warm early Eocene sea represented by the London Clay. It belonged to the extinct family Tumidocarcinidae. Like many bottom-dwelling crabs, it was probably an opportunistic predator and scavenger, feeding on small invertebrates and edible remains while relying on a strongly built carapace for protection.

The species is particularly important because it is the type species of Xanthilites. Modern revisions have greatly restricted that genus around X. bowerbanki, making this crab a useful reference point for understanding the diversity and evolution of robust early Eocene true crabs.

Quick Identification

Look for: a broad, strongly vaulted crab carapace with deep regional grooves, a finely granular surface and a conspicuously spined front and outer margins.

Diagnostic Features

  • Carapace wider than long, with length about 80% of maximum width.
  • Carapace strongly vaulted lengthways, especially across the anterior third.
  • Dorsal regions are swollen, finely granular and separated by deep grooves.
  • Front is narrow and projecting, with four spinous projections including the inner-orbital spines.
  • Each anterolateral margin bears four spines excluding the outer-orbital spine; the orbits are rimmed and lack fissures.

Fossil Details

Typical size
Centimetre-scale carapace; a secure species-wide size range is not established.
Fossil material
Carapace, Claw / Chela
Preservation
Carapaces can be incomplete, with the frontal and anterolateral spines especially vulnerable to breakage. Abrasion may weaken the fine granulation and deep grooves that define the dorsal regions. Species-level identification is strongest when the overall outline, front and several lateral spines are preserved together.

Similar Species

Recorded Fossil Sites

References

  • J. S. H. Collins; C. J. T. Mellish; A. J. Ross; P. R. Crabb; S. K. Donovan. (2020). A guide to the fossil Decapoda (Crustacea: Axiidea, Anomura, Brachyura) of the British Isles. Proceedings of the Geologists' Association, 131(1), 19–50 View reference
  • Thomas Bell. (1857). A monograph of the fossil malacostracous Crustacea of Great Britain. Part I. Crustacea of the London Clay. Monograph of the Palaeontographical Society, 10, i–viii, 1–44. Palaeontographical Society, London View reference
Last Reviewed
2 September 2026 Reviewed by Sam Harris