Tympanotonos funatus

Tympanotonos funatus

(J. de C. Sowerby, 1814)

Common name Mud Snail
Fossil group Molluscs
Order Cerithiida
Family Potamididae
Genus Tympanotonos
Taxonomic status Accepted
Geological age Ypresian

Summary

Tympanotonos funatus was a tall potamidid mud snail. Potamidids are characteristic inhabitants of warm intertidal and estuarine mudflats and mangrove-margin environments, where they graze and process organic-rich surface material.

The shell is strongly turreted and ornamented with spiral cords and nodules. Its small aperture and short anterior channel distinguish it from many freshwater high-spired snails.

Quick Identification

Look for: a tall turreted shell with many whorls, strong spiral cords and rows of nodes, plus a relatively small aperture with a short anterior channel.

Diagnostic Features

  • Shell tall and turreted with numerous whorls.
  • Spiral cords are strong and continuous around the whorls.
  • Axial elements intersect the cords to produce rows of nodules or tubercles.
  • Aperture is relatively small compared with the height of the shell.
  • Anterior end forms a short channel or notch rather than a long siphonal canal.

Fossil Details

Typical size
Early Eocene specimens can reach several centimetres high; comparable material is around 30–40 mm.
Fossil material
Shell, Internal Mould / Cast
Preservation
The long spire commonly loses its apex and the aperture is often incomplete. Nodules and spiral cords remain visible after moderate abrasion, but strongly rolled fragments can be hard to distinguish from other cerithioideans.

Similar Species

Recorded Fossil Sites

Synonyms & Previous Names

Potamides funatus; Tympanotonos (Eotympanotonos) funatus

References

  • Rundle, A. J. (1970). Report of a Field Meeting to Abbey Wood, Kent. Tertiary Times, 1, 20–23 View reference
  • Spijkerman, E.; van Nieulande, F. A. D.; Wesselingh, F. P.; Reich, S.; Tracey, S. (2015). Pourcy (Paris Basin, France): preliminary assessment of an early Eocene NW European tropical coastal environment from molluscs and vertebrate fossils. Cainozoic Research, 15(1–2), 155–180 View reference
Last Reviewed
22 August 2026 Reviewed by Sam Harris