Microfossils from Watton Cliff - Your complete guide

Collecting Microfossils

Microfossils are mostly found in the soft sandy beds from the Forest Marble, these are more orange colour and crumble in your hands, although many other beds yield small fossils such as mammals, reptiles etc. Since the Forest Marble is found at the very top of the cliff, you need to search the blocks of fallen material at the base of the cliff. Brachiopods and corals can be found from the underlying Frome Clay, but these are not common.

Although the cliff-top exposures look fairly thin, they are actually the most complete section of the Forest Marble Formation found in Dorset, the section is some 25m in thickness, but only two beds are good for microfossils. These can be detailed below.

Calcirudite or Mammal Bed	Cross-bedded shelly limestone, sandy and oolitic in places, with irregular clay seams. Some lignite and bivalves within this bed. This bed is good for crinoids, bivalves, plant remains, fish remains and of course mammals.
Boueti Bed	Hard, sandy marl stained reddish-brown. This bed is good for bivalves, brachiopods, crinoids, ossicles and serpulids.

Bag up your samples in heavy duty bags, but make sure you write on them what bed the samples are from and make a note of any important information.

The best way to process your samples is to break them down with acid. This will separate the fossils. If this is not possible, then the material is actually quite soft and small pieces can easily be crumbled in your hands. This method may cause some fossils to become damaged, however, strong acid can be hard to source these days due to strict regulations on selling it.

larger lumps can be broken down into smaller pieces using a small hammer. Once you have the sample broken down, use water to wash the sediments and remove any sand or ideally use a sieve and wet-sieve the samples at 500, 200, and 150 microns. Sieves can be purchased from us, (under the 'What to Bring' section).

You will need a microscope to view these. We sell a wide range which can be found under 'What to bring' page. Our most recommended model is the IMXZ. We can also help you with setting up your digital camera or viewing onto a TV.

Microfossils from Watton Cliff are well-documented. In particular, four mammal species have been found. These are Eleutherodon oxfordensis, Amphilestes broderipii, Borealestes serendipitus and Trenchnotheria indet. A single tritylodont tooth has also been recovered from Stereognatbus sp.

Fish teeth and fragments, shark teeth(Asteracanthus sp.), crocodile remains (Teleosaurus sp.), reptile remains, amphibians, crinoid fragments (Apiocrinites sp.), bryozoans and ostracods are also found. Small brachiopods including Goniorhynchia boueti, Avonothyris langtonensis, Ornithella digona and bivalves including Chlamys vagans, Camptonectes sp., Plagiostoma sp., Praeexogyra sp are also commonly found here.