HUGE Lytoceras aff. (fimbriatum) (Sowerby)
Lytoceras aff. (fimbriatum) (sowerby)
I have just finished preparing this large and rare Lytoceras ammonite from the Jurassic green ammonite beds (GAB) of Dorset.
It was found by the experienced local professional fossiler David Halmkin. It is the second Lytoceras of this size that he has found.
This specimen measures 21 cm approx at its widest point and has been prepared with the delicate flanges intact. The rare inclusion of the termination on this ammonite is also preserved. This is where the lines of the ammonite become compacted near the entrance / mouth border. This is a very fragile part of the ammonite and is often lost during preservation.
This fossil has 5% restoration to the venter /keel. Also the outer edge of the ammonite leading towards the mouth border has been eroded by coastal conditions.
During preparation showing the delicate flanges being exposed. Great care has to be taken as they are paper thin in places and semi-translucent as a result. They are best left with a supporting wall of matrix until the end of the preparation to help protect them. Once one side of a flange has been exposed it is important to paint it with thin superglue so that the opposite side can be revealed.
W.D Lang reported the Lytoceras ammonite as being absent from the green ammonite beds, having noted it only being present as far up as the Belenmite marl, when he wrote his papers on the lower lias ammonites in the 1900’s.