Cimomia imperialis
Cimomia imperialis
Summary
Cimomia imperialis was a robust chambered cephalopod swimming in the London Clay sea. Its large coiled shell acted as a buoyancy system, allowing the animal to move through the water while using jet propulsion for short bursts of movement and manoeuvring.
Like living nautiloids, it was probably an opportunistic predator and scavenger. It may have searched close to the seabed for crustaceans, other small animals and carrion, using numerous tentacles to investigate and handle food. Larger individuals would have been among the more conspicuous free-swimming molluscs in this ecosystem.
Quick Identification
Look for: a robust coiled nautilus with broad rounded whorls, a visible umbilical region and comparatively simple curved sutures rather than the strongly zig-zag sutures of Aturoidea ziczac.
Diagnostic Features
- Shell is robust, planispiral and strongly chambered.
- Whorls are broad and rounded rather than narrowly compressed.
- Umbilical region remains visible in well-preserved specimens.
- Septal sutures are comparatively simple and gently curved.
- Adult shell is substantially larger and more massive than Aturoidea ziczac.
Fossil Details
Similar Species
Recorded Fossil Sites
London Clay Formation
Synonyms & Previous Names
References
- Edwards, F. E. (1849). A monograph of the Eocene Mollusca, or descriptions of shells from the older Tertiaries of England. Part I. Cephalopoda. Palaeontographical Society Monograph, 2, 1–56. Palaeontographical Society, London View reference
- Hewitt, R. A. (2002). A review of the Early Eocene nautiloids of the London Clay Formation (upper division C to lowest division E) of south-east England, with particular reference to concretionary horizons and faunules in the offshore facies strata at Southend-on-Sea, Essex and in the adjacent cliffs of the Isle of Sheppey, Kent. Tertiary Research, 21(1–4), 39–50 View reference