Ammonites are very rare in the Chalk. They tend to be badly preserved - their shell was made of aragonite which dissolved during or after fossilisation. There are a few horizons where they are more common - the Red Chalk, the Grey Bed, near the Black Band Member, and in the highest part of the East Yorkshire Campanian.

Ammonites usually make excellent Zone fossils - but their rarity in our region means that they are not used, with the exception of the Discoscapahites.

[click on the thumbnail pictures to view larger version]

  Turrilites from South Ferriby, Cenomanian age.
Part of a large Austiniceras at South Ferriby, Cenomanian age.
A complete Autiniceras from South Ferriby, now in Hull Musems

Austiniceras at Melton Quarry

unidentified ammonite at Kiplingcotes. Turonian age.

A rare ammonite from Selwicks Bay (upper Coniacian)

Discoscaphites from Sewerby, Campanian age

Discoscaphites from Bridlington, Campanian age