Phyllodus toliapicus

Phyllodus toliapicus

Agassiz, 1844

Common name Bonefish
Fossil group Bony Fish
Order Albuliformes
Family Phyllodontidae
Genus Phyllodus
Taxonomic status Accepted
Geological age Thanetian and Ypresian

Representative Specimens

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

Identification Examples

Choose a fossil site to view photographed reference specimens.

Summary

Phyllodus toliapicus was a specialised phyllodont fish with large dental plates built for crushing. Its mouth carried repeated rows of rounded to elongate teeth packed into a durable pavement. This is strong anatomical evidence for durophagy — feeding on hard-shelled prey such as molluscs and crustaceans — although the precise prey species are not known.

The tooth plates are much more commonly preserved than the rest of the skeleton, so the feeding apparatus provides most of what is known about the animal. Phyllodus occupied a trophic niche very different from the long-jawed pursuit predators of the London Clay, processing resistant benthic food with repeated replacement teeth.

Quick Identification

Look for: a thick phyllodont tooth plate carrying several rows of rounded to oval crushing teeth, with the largest teeth concentrated toward the central functional surface and smaller teeth toward the margins.

Diagnostic Features

  • Dentition forms a broad multi-rowed pavement rather than a single marginal tooth row.
  • Functional teeth are rounded to oval with low, smooth crushing crowns.
  • Central teeth are larger than those at the margins of the plate.
  • Replacement teeth are stacked beneath or behind the functional series within the thick plate.
  • Tooth crowns are closely packed, producing a continuous crushing surface with little exposed bone.

Fossil Details

Typical size
Not reliably established from the published isolated dental material.
Fossil material
Tooth, Tooth Plate
Preservation
Dental material is often separated from the jaw and may be heavily worn. Crushing crowns can lose their original relief and pointed teeth can lose tips, edges or basal structures; incomplete specimens should be identified conservatively.

Similar Species

Recorded Fossil Sites

Wrabness Member

Harwich Formation
Confirmed
Harwich

References

  • Casier, E. (1966). Faune ichthyologique du London Clay. 496 pp.. Trustees of the British Museum (Natural History), London View reference
  • Ebersole, J.A.; Cicimurri, D.J.; Stringer, G.L. (2019). Taxonomy and biostratigraphy of the elasmobranchs and bony fishes (Chondrichthyes and Osteichthyes) of the lower-to-middle Eocene (Ypresian to Bartonian) Claiborne Group in Alabama, USA, including an analysis of otoliths. European Journal of Taxonomy, 585, 1–274 View reference
  • Friedman, M.; Beckett, H. T.; Close, R. A.; Johanson, Z. (2016). The English Chalk and London Clay: two remarkable British bony fish Lagerstätten. Geological Society, London, Special Publications, 430(1), 165–200. Geological Society of London, London 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
Last Reviewed
26 August 2026 Reviewed by Sam Harris