Fossil Hunting - Bracklesham Bay, West Sussex

Illustrated are a handful of the fossils that we found at Bracklesham Bay, over two visits on Sunday 11th and Monday 12th of February 2018. An attempt to correctly identify some of them has been made using David Bone's excellent guide as referenced below.

Bracklesham Bay, Sunday - looking south east

exposed Turritella shell

exposed Venericor sp. shell

the results of Sunday's collecting

cattle egret (Bubulcus ibis) Warblington 12th February

Bracklesham Bay, Monday - looking south east

Bracklesham Bay, Monday - looking north west 

the splendid results of Monday's collecting

An attempt at identification:

fragments of Iron pyrites

possibly Venericardia carinata from the Cardita bed

possibly Venericardia planicosta from the Cardita bed

David Bone explains that recent radiometric dating has confirmed that the Turritella bed is 45 million years old, as is the similarly aged Cardita bed.

two different shell species from the Turritella bed?

If my understanding is correct from David Bone's descriptions the three unclassified Turritella shells above comprise of two different species, the larger shell with rounded whorls one specie; and the two smaller shells "with stepped, angular whorls" a second specie.

Left: fossilised oyster (Cubitostrea elegans)?

Right: unfossilised oyster?

Nummulites laevigatus washing out of the beds

form left by washed out Nummulites laevigatus

Nummulites laevigatus

Once you have got your eye in, you will see that there are simply loads of these small round fossils called Nummulites laevigatus washing out of the fossil bed along the beach. Apparently they are the fossilised remains of the calcium carbonate shells of Foraminifera - themselves comprising of a microscopic single celled organism which builds a complex structure in the presence of a symbiotic photosynthesizing algae.

 a collection of shark's teeth

shark's tooth detail showing vertical striations

Bone indicates that fossils from up to 60 species of shark and ray species can be found washing out of the Turritella and Cardita beds.

fragments of ray plates

Unknown item

I have to confess that I do not know where to start with this item? Fossilised Bone? Coral? Other? Possibly not even a fossil at all? I picked it up, as it looks distinctly organic in form? I will attempt to find a forum or expert to identify it going forward.

three views of probable flint shell fossil

Another interesting find was of a probable fossilised shell, but this time preserved in flint rather than within the sediments of the Bracklesham beds? You can see its superficial resemblance to Venericardia spp in the last two photographs. Bone explains that flint fossils belong to an earlier period than the Bracklesham beds - dating to around 65 and 98 million years old.

Addendum

April 17th 2018 David Bone very kindly responded to my email enquiry regarding both the "unknown item" and the flint above. Of the unknown item he suggests that it is possibly a marine sponge preserved in flint - but subject to modern marine borings? The second a flint impression of a bivalve from the Upper Cretaceous period.

Reference

Bone, D. (2016) The Geology and Fossils of Bracklesham Bay and Selsey Limanda Publishing, Chichester