Zanthopsis nodosa
Zanthopsis nodosa
Summary
Zanthopsis nodosa was a sturdy true crab covered with conspicuous raised bosses and nodules. It probably spent its life on the seabed feeding opportunistically on small animals and carrion, protected by a strongly built shell.
The knobbly carapace may have strengthened the shell, disrupted its outline or made the crab more difficult for predators to handle. Whatever the exact advantage, it gave Z. nodosa a very different appearance from smoother London Clay crabs and highlights the variety of defensive body forms in the fauna.
Quick Identification
Look for: a broad robust Zanthopsis carapace with conspicuous rounded nodules or swellings on the dorsal regions, combined with strong regional grooves and margins.
Diagnostic Features
- Carapace broad and strongly built.
- Dorsal surface carries conspicuous nodules or swollen bosses.
- Gastric, cardiac and branchial regions are clearly defined.
- Nodose ornament is more conspicuous than in Zanthopsis leachii or Z. dufouri.
- Species-level identification should confirm the nodules together with the complete regional and marginal pattern.
Fossil Details
Similar Species
Recorded Fossil Sites
No fossil-site occurrences have yet been recorded for this species.
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