Ardiodus mariotti
Ardiodus mariotti
Common name
Mackerel relative
Fossil group
Bony Fish
Order
Scombriformes
Family
incertae sedis
Genus
Ardiodus
Taxonomic status
Taxonomically Uncertain
Geological age
Thanetian
Summary
Ardiodus mariotti was an early Palaeogene marine predatory bony fish known only from isolated teeth. The teeth are short, stout and strongly curved, with smooth cutting edges and, in many specimens, a small barb near the tip. That construction is best interpreted as a grasping and piercing dentition suited to seizing mobile prey such as smaller fishes or other nekton, although direct dietary evidence is unknown.
The species was historically treated as a scombroid or mackerel-like fish, but its exact family remains unresolved because no diagnostic associated skeleton has been found.
Quick Identification
Look for: a short, stout, strongly curved tooth with a round to semicircular base, two smooth lateral cutting edges and, when preserved, a small apical barb.
Diagnostic Features
- Tooth crown is short, stout, subconical and strongly curved.
- Tooth base is circular in larger examples and may be semicircular in smaller or more slender teeth.
- Crown becomes more compressed labiolingually towards the apex.
- Two lateral cutting edges are smooth and non-serrated.
- A small apical barb occurs in most well-preserved teeth; fine surface striation is variable.
Fossil Details
Typical size
Known teeth are small; the largest crown reported in modern revision is about 8 mm. Whole-body length is not securely known.
Fossil material
Tooth
Preservation
Ardiodus is normally represented by isolated teeth. The apical barb and cutting edges are easily damaged by wear or breakage, and abrasion can round the tip or obscure the transition from the broad base into the compressed apex. Species-level identification is strongest in complete teeth preserving the base, curvature and apical region together.
Similar Species
Recorded Fossil Sites
Beltinge Fish Bed
Upnor Formation
Confirmed
Reculver Sand Member
Thanet Formation
Confirmed
References
- Monsch, K. A. (2005). Revision of the scombroid fishes from the Cenozoic of England. Transactions of the Royal Society of Edinburgh: Earth Sciences, 95(3–4), 445–489 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
- White, E.I. (1931). The vertebrate faunas of the English Eocene. I. From the Thanet Sands to the Basement Bed of the London Clay. 121 pp.. British Museum (Natural History), London View reference
Last Reviewed
22 August 2026
Reviewed by
Sam Harris