Duplexdens (Scombrinus) macropomus

Duplexdens macropomus is a rare Scombrid fish from the London Clay which has similarities with the extant King Mackerel or Kingfish (Scomberomorus cavalla) pictured here.

This streamlined fish has an elongated skull with sharp, conical-shaped straight teeth regularly spaced on both the upper and lower jaws. The lower jaw also features small secondary teeth on the outside of the jaw.

These have been found in Divisions D/E of the London Clay on the Isle of Sheppey.

Scomberomorus cavalla (Cuvier, 1829) Observed in United States of America by norops (licensed under http://creativecommons.org/licenses/by-nc/4.0/)

Distinguishing Characteristics:

Sclerotic ossicle present in orbit (1)
Sharp, regularly spaced teeth (2)
Elongated skull ending with a pointed-maxilla bone (3)

Primary Example: Dan Hogburn Specimen

3D Scan: Dan Hogburn Specimen 1

3D scans undertaken by Tom Sermon with permission.

Additional examples: Fred Clouter Specimen 1

Fred Clouter Specimen - As found washing out of the clay on the Isle of Sheppey

Photograph courtesy of Fred Clouter

3D Scan: Fred Clouter Specimen 1

3D scans undertaken by Tom Sermon with permission.

Micro-CT scan: Fred Clouter Specimen 1

3D scans undertaken by Tom Sermon with permission.

Additional examples: NHMUK PV P 4145

CT Scan: NHMUK PV OR 37759

3D scans taken by the Natural History Museum, London and provided to Tom Sermon with permission to publish.

References

Casier, E. (1966) Fauna ichthyologique du London Clay. British Museum Natural History London, 1966, 1-496
Monsch, K (2005) Revision of the scombroid fishes from the Cenozoic of England
Raynor, Mitchell, Clouter (2009) London Clay Fossils of Kent and Essex