In 1986 I spent a lot of time in a clay quarry at Farcet near Peterborough. This site exposed the Pleistocene surface deposits and the Oxford Clay down to the Cornbrash. The site was a rich source of fossils from the Jurassic, including remains of a giant fish called Leedsichthes. Ammonites, belemnites and oysters were the most abundant fossils. My main recollection was how the clay would adhere to anything. As the days progressed your wellies would get heavier and heavier on your feet until you had to stop and clean off the clay.
Looking through my fossil collection reminded me of the abundance of fossils in these Jurassic sediments.
The common belemnites in ther Oxford Clay were;
1. Cylindroteuthis puzosiana, a distinct and large species,
2. Pachyteuthis species,
3. Cylindroteuthis species,
4. Belemnopsis species,
5. Hastites species.
The C. puzosiana was by far the commonest species found and also the largest.
Ammonites were also found in the Oxford Clay deposits, like this Sigaloceras species, showing its fine suture lines. Some species were also preserved with the aragonite shell intact. Other fossil ammonites showed signs of tooth marks from predation by marine reptiles.
Alongside the draws of Oxford Clay fossils, I found a number of sectioned and polished ammonites. These are always interesting and make fine display specimens.
1. Dactylioceras species from Whitby in Yorkshire, showing an even and regular growth pattern with simple chambers.
2. Oppelia fallax, with the large body chamber preserved.
3. Hildoceras bifrons with its large internal chambers.
This is a rather fine sectioned specimen of the spiny ammonite, Laparoceras cheltiensis, collected at Moreton in Gloucestershire. The crystal filled chambers twinkle in the sunlight.