Nautili
Nautili occur fairly frequently on Sheppey. Of the six species found on the island only Cimomia imperialis can be described as common.
Nautilus Cimomia imperialis collected in situ from nodule band 'G'
Unusually preserved A. ziczac (mature Female?)
Cimomia imperialis (J. Sowerby) is the largest and the most common nautilus found on Sheppey. The diameter is slightly more than the width with a gently curving edge profile. S shaped septa with a deep open umbilicus. Central siphuncle.
C. imperialis Section showing internal structure
C. imperialis showing crushed centrum
Aturia ziczac preserved in pyrite - This is the usually how this species is found in the pyrite accumulations. Normally no larger than 80mm, narrow in section with an exagerated S-shaped curve. Open umbilicus.
Simplicioceras centrale - Normally no larger than 80mm diameter. Round in section with staight septa. Open umbilicus
Euciphoceras regale Larger than S. centale which also has staight septa. It is narrow in profile with a gently curving profile. Septa are staight and the umbilicus is closed. A calcite plug covers the central hole.
Deltoidonautilus cassinianus found by thomas Harrison. Diameter up to 120mm and quite narrow with S-shaped septa. (not as severe as A. ziczac ) Open umbilicus
Two small specimens of Deltoidonautilus cassinianus
Deltoidonautilus sowerbyi - middle of a much larger specimen which had collapsed the outer chambers Diameter about 150mm upwards. Narrower in width than C. imperialis with a sharply curved edge profile. S shaped septa with an open umbilicus and a central siphuncle.