Abbey Wood Fossil Hunting

The designated fossil pit in Lesnes Abbey Woods, southeast London, is famous for its early Eocene shark teeth and shell-rich sediment. Careful sieving can also reveal fish remains and much rarer vertebrate fossils. Follow the site’s limits on digging and material removal, and arrange organised visits with the council before travelling.

FIND FREQUENCY: ♦♦♦♦♦ – Shark teeth and shells are characteristic finds, with much rarer small vertebrate remains. Results vary between samples.
CHILDREN: ♦♦♦♦♦ – A good setting for supervised shallow digging and sieving; sharp flint, holes and uneven woodland paths still need care.
ACCESS: ♦♦♦♦♦ – Reached by woodland paths near Lesnes Abbey. Abbey Wood Station is about ten minutes’ walk from the woods.
TYPE: – A designated fossil pit where controlled shallow digging and sieving are allowed under the manager’s rules.

DIRECTIONS

♦ Head for Lesnes Abbey and the woods beside Abbey Road in the London Borough of Bexley. Abbey Wood is the nearest railway station, about ten minutes’ walk from the woods.
♦ Bexley Council identifies Gayton Road and Felixstowe Road car parks near the station. Limited roadside spaces on Abbey Road and New Road are subject to current signs; there is no public car park within the woods.
♦ Enter by the established woodland paths and follow signs to the designated fossil pit. Do not dig elsewhere in the park or beside the abbey ruins.
♦ Original locality reference: 51.487102, 0.13085961. Follow the signed pit approach rather than treating the reference as a parking pin.

FOSSIL HUNTING

At Abbey Wood the productive material is the sandy, pebbly Lessness Shell Bed, rather than any patch of soil in the woods. Within the designated pit, gently sieve permitted loose or shallowly excavated sediment and spread the residue thinly in a tray. Check between the broken shells and rounded flints instead of looking only for conspicuous large teeth. A coarse fraction is useful for larger finds, but fine material needs a hand lens: scientific screen-washing has recovered specimens that ordinary hand-picking would miss. Work within the manager’s digging and removal limits; a geological bed thickness is not a permitted digging depth.

Shark teeth. Look for a smooth crown with deliberate cutting edges and a root of different texture. A black flint splinter can be shiny and pointed too, so colour alone is unreliable. The site’s illustrated fossil guide records Striatolamia macrota and Sylvestrilamia teretidens. The latter was originally described from Abbey Wood and appears as Synodontaspis teretidens in older accounts. Its relatively slender front teeth have an almost straight central cusp and small lateral cusplets; side teeth look different. The specialist revision stresses how difficult this species can be to separate from other sand-shark teeth. Keep the root and tiny side cusplets intact, and compare both faces rather than naming every narrow tooth from its outline.

Ray teeth and other fish. The small crushing teeth of Hypolophodon sylvestris are a contrasting target: their low, rounded-to-angular working crowns look quite unlike a tall shark cusp. This ray is well documented at Abbey Wood and is also represented by dermal denticles. The angel shark Squatina prima is another recorded form; it is a shark, despite being illustrated beside ray remains in some guides. Tiny fish otoliths, or ear stones, are particularly important here. Examine small sculptured objects carefully rather than discarding everything without a sharp point. Fish bones, scales and vertebrae add to the residue, but worn fragments often merit a general identification.

Shells. Bivalves and snails make up much of the shell bed and deserve as much attention as the teeth. The local identification guide illustrates oysters, Nucula, Glycymeris and globular Euspira snails, alongside more slender, high-spired gastropods. Look for hinge areas on broken bivalves and the aperture and whorl shape on snails. These features are more informative than size alone. Many shells are fragmentary: lift a promising specimen with its supporting sediment rather than shaking or pulling it free. The shell mixture records several neighbouring coastal habitats, so one handful need not represent a single living community.

Unusual vertebrates. Turtle, crocodilian and bird remains occur, while mammal teeth are scientifically important but much rarer visitor finds. Abbey Wood has yielded named mammals such as the primate Cantius eppsi and the small hoofed mammal Hyopsodus wardi; this is evidence of the site’s research importance, not an expectation for each sieve. A minute tooth with several cusps should be kept safely for expert examination. Do not attempt to identify it by resemblance to a shark tooth or scrape away its remaining matrix.

The original guide describes a 1999 excavation that recovered nine mammal teeth assigned to Sparnacomys, Paramys pourcyensis and possibly Pseudoparamys, together with an upper-left P4 and an M2 attributed to Wyonycteris. This is retained as the historical guide’s account rather than a new revision of those identifications. Keep unusual vertebrate finds and associated matrix together, record their precise position and notify the ranger or a museum before preparation. There is no dependable number of teeth per bucket; careful examination is more useful than collecting larger volumes.

A chronological record of fossil discoveries, geological research and conservation milestones associated with Abbey Wood.

Early twentieth century – Systematic excavations begin
Early excavations established Abbey Wood as a source of terrestrial vertebrates within the Blackheath deposits. The site later became a key comparison point for early Eocene mammal faunas.

1932 – Mammals formally described
Cooper described important Abbey Wood mammal material, including the primate later called Cantius eppsi and the animal later recognised as the bat Eppsinycteris anglica. Subsequent reinterpretation changed their classification without changing the importance of the locality.

1962 – Primate reassigned to Cantius
The Abbey Wood primate originally named Protoadapis eppsi was made the basis of the genus Cantius, clarifying its distinction from superficially similar early primates elsewhere in Europe.

1969 – A surviving multituberculate identified
Kühne described the Abbey Wood multituberculate originally named Charlesmooria childei, subsequently assigned to Ectypodus. It documented a late representative of a much older mammalian lineage.

1979 – Two mammal species named
Lessnessina packmani and Hyopsodus wardi were described from Abbey Wood jaw fragments and teeth, making the site the type locality for both species.

From 1992 – Repeated scientific excavations
Annual excavations organised by the Tertiary Research Group renewed systematic sampling. Fine screening revealed small mammal material that conventional surface searching easily misses.

1996 – An early bat recognised
Re-examination of the animal originally called Adapisorex anglicus recognised an early sheath-tailed bat and established the combination Eppsinycteris anglica.

2010 – Mammal fauna and stratigraphy revised
Jerry Hooker’s monograph brought together the early Eocene mammal fauna and reconsidered the position and sedimentary relationships of the Lessness Shell Bed. The shell bed was placed within the Blackheath deposits.

References
Aldiss 2014, Palaeogene stratigraphical framework, OR/14/008
BGS Lexicon: Lessness Shell Bed
Benton, Cook and Hooker 2005, British Tertiary fossil mammal sites, GCR32

GEOLOGY

Abbey Wood’s fossils come from an early Eocene coastal deposit, about 55 million years old. In the current BGS framework the Lessness Shell Bed belongs to the Blackheath Member of the Harwich Formation. “Lesnes” is the spelling used for the abbey and woods, while “Lessness” is the formal bed name. Some mammal publications use Blackheath Formation instead; this is an alternative classification of the same deposit, not another formation stacked into the pit.

The shell bed is a patchy concentration of shells in fine- to medium-grained sand, with scattered well-rounded flint pebbles. It can thin from about 2 m to nothing over only a few metres and interleave with buff, comparatively shell-poor sand. White bedded sand and a thin iron-rich layer occur beneath the fossil-bearing interval; gravel-rich deposits occur above. This lens-like arrangement explains why neighbouring samples can give very different results. It also means the simple appearance of a sandy pit conceals more variation than a uniform horizontal “fossil layer” would suggest.

The rounded flints and mixed shells record erosion, transport and concentration close to a changing shoreline. Marine and brackish-water animals occur with remains carried from nearby land, including small mammals. Such mixing helps explain the unusually varied fossil assemblage. The Blackheath deposits occupy an erosional surface cut across older sediments, rather than preserving every older formation beneath every part of the woods. Separate Chalk exposures belong to the Late Cretaceous and must not be confused with the much younger shell bed.

The public pit is a limited, managed exposure rather than a complete permanent geological section. Upper pebbly material, soil and old spoil can obscure or mix the original layers. A tooth found in loose surface residue can still be interesting, but its exact horizon should remain unassigned unless the bed was observed directly. The detailed account below retains the local sand, shell-lens, iron-pan and gravel relationships without implying that visitors should excavate to expose them.

Detailed geology and stratigraphy of Abbey Wood.

THAMES GROUP

The fossil pit exposes early Eocene deposits near the base of the Thames Group. Marine and brackish-water shells occur together with transported terrestrial remains, so the assemblage records both the coastal water body and nearby land.

Harwich Formation

The current BGS framework retains the Blackheath Member within the Harwich Formation. Some mammal literature uses “Blackheath Formation”; that is an alternative classification of the same deposits, not an extra unit above or below them.

Blackheath Member

The local deposit comprises sands, rounded black flint gravel and shell-rich lenses. Its erosional base cuts across older units: in the Abbey Wood area, BGS records the Blackheath Member resting on strata ranging from lower Upnor Formation to lower Thanet Formation within about 300 m. These lateral relationships do not justify drawing a complete older succession beneath the public pit. The present woodland also contains separate Chalk outcrops, with the Chalk belonging to the Late Cretaceous.

Bedded white sand and thin iron pan

White bedded sand with sparse Ophiomorpha burrows occurs beneath the shell-bearing interval. The detailed modern account records a thin iron pan below the shell bed. Neither has a demonstrated uniform thickness for the whole pit; the iron pan is distinct from the basal gravel.

Lessness Shell Bed (locally 0–2 m)

Fine- to medium-grained sand contains shell lenses and scattered well-rounded flint pebbles. Its thickness changes from absent to about 2 m over only a few metres, and it interdigitates with less fossiliferous sand. The fauna includes marine and brackish molluscs, fish teeth, reptiles, birds and a diverse terrestrial mammal assemblage. “Lessness” is the stratigraphic spelling; “Lesnes” is used for the abbey and woods. A maximum bed thickness does not imply that visitors may dig to that depth.

Non-shelly buff sand

Buff-coloured non-shelly sand interleaves with and overlies the shell-rich lenses. The contact is laterally variable rather than a simple flat boundary across the site. Poor fossil yield in a sandy patch can therefore reflect facies change, not exhaustion of the whole fossil bed.

Upper pebble beds and disturbed surface cover

The upper Blackheath succession includes substantial pebble beds, locally resting directly above the shell-bearing interval. Near the ground surface, disturbance and soil obscure original bedding. Surface spoil may mix material from several parts of the pit and should not be assigned an exact bed without direct observation.

References

Aldiss 2014, Palaeogene stratigraphical framework, OR/14/008
Benton, Cook and Hooker 2005, British Tertiary fossil mammal sites, GCR32
BGS Lexicon: Lessness Shell Bed
UK Fossils, Abbey Wood (field inspection 2016)

SAFETY

Do not dig deeper than two feet, undercut sides or leave large or deep holes open. Refill them before leaving and follow any ranger instructions.

Sharp flint, loose sediment and muddy uneven paths require sensible footwear and direct supervision of children. A managed woodland pit is not free of hazards.

EQUIPMENT

Bring a bucket, small containers, tweezers, a hand lens and suitable sieves for the permitted activity. The original guide recommends a fine mesh around 0.5 mm alongside a coarser sieve; handle the retained fraction gently and observe the material-removal limit.

Use water only where the manager allows it and facilities are available. Do not assume an on-site water supply, and do not discharge muddy residues into woodland drains.

CLEANING AND TREATING

Place isolated teeth in small padded containers and retain supporting matrix around fragile bone and shell. Examine dry fine fractions under magnification before unnecessary handling.

Wash only robust, identified material where it is permitted and will not break down. Avoid acids and indiscriminate glue. Keep unusual mammal or bird material unprepared with its associated matrix for expert assessment.

IDENTIFY YOUR FINDS

FURTHER READING

BGS Lexicon: Lessness Shell Bed
Aldiss 2014, Palaeogene stratigraphical framework, OR/14/008
Benton, Cook and Hooker 2005, British Tertiary fossil mammal sites, GCR32
Lesnes Abbey Woods: official geology and collecting rules

ACCESS RIGHTS

Collect only within the designated fossil pit. The site-manager limits are no more than 2 kg of material removed, digging no deeper than two feet, and refilling large or deep holes. Follow any additional instructions displayed on site.

Schools, groups and professional digs must book with the council. The site requests at least one month’s notice for group visits and states that charges apply. Arrange permission through the current Lesnes Abbey Woods/Bexley Council contact before planning an organised dig.

It is important to follow our ‘Code of Conduct’ when collecting fossils or visiting any site. Please also read our ‘Terms and Conditions’.

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