Lavernock Fossil Hunting

1883 – Storrie’s Fish Bed is documented
Storrie documented the local fish-bearing horizon later known as Storrie’s Fish Bed. Subsequent work distinguished it from other vertebrate-rich layers, an important caution against treating every dark bone-bearing rock at Lavernock as the same bed.

1922 – A Lavernock ammonite is figured and measured
Trueman illustrated an ammonite from near Lavernock Station in the wider Lavernock area as Schlotheimia cf. hagenowi, recording dimensions and sutures. Plate 9A’s explanation gives the historical “liasicus sub-zone”, while a separate footnote refers to lower historical Angulata Zone material; these are not treated as a verified modern coastal-bed assignment. The provisional historical identification and locality remain useful, but the source supplies no museum accession and does not establish a new type series.

1980–1987 – A detailed reference framework is established
Formal work on the Penarth Group was followed by the Cardiff geological memoir’s detailed coastal mapping, Westbury sedimentary cycles, fossil-distribution chart and Jurassic subdivisions. The reference area combines Lavernock, Penarth and St Mary’s Well Bay rather than making one outcrop the type of every unit.

2014–2016 – Dracoraptor is recovered and named
Nick and Rob Hanigan recovered associated dinosaur-bearing blocks in March 2014, and Sam Davies found additional foot material on 20 July 2015. The partial skeleton was named Dracoraptor hanigani in January 2016 and is held by Amgueddfa Cymru. Its original horizon was inferred from the fallen blocks’ lithology; the later foot and museum casts are not additional dinosaurs.

2020–2021 – A small ammonite changes the boundary interpretation
The description of Neophyllites lavernockensis, published online in 2020 and in print in 2021, linked an ammonite to the White Lias and supported a lower local position for the Triassic–Jurassic transition than the traditional first Psiloceras planorbis. The holotype’s bed was inferred from adhering matrix, while a second worn ammonite was observed in situ.

2024 – Vertebrate assemblages and boundary correlations are reassessed
A re-study of the basal vertebrate material highlighted bony-fish teeth and the effects of transport on the assemblage. Separate magnetostratigraphic work added evidence for correlating the transition, while retaining uncertainty rather than treating a conspicuous lithological boundary as an exact global time marker.

2026 – A specimen found in 2010 helps resolve fish identities
A jaw element found and prepared by Jonathan Bow in 2010 was studied as Saurichthys, helping separate it from Birgeria acuminata after teeth of the two had been grouped under Severnichthys. Specimen NMW2023.1G.1 came from a distinct coprolitic shale above the basal conglomerate; its accession year is not its discovery date.

Scope and independent logs. Lavernock Point, Lavernock Bay and St Mary’s Well Bay are named separately throughout this account. The guide covers the older rocks north/east of the Point and the Jurassic shore westwards, but no one exposure contains every measured bed. The memoir’s six Westbury cycles, Sykes’s measured bone-bed section, Gallois’s St Mary’s Well Bay reference section and the dinosaur paper’s bed numbers are independent schemes unless a published correlation explicitly links them.

MERCIA MUDSTONE GROUP

Branscombe Mudstone Formation

Historical red marls. Red-brown, locally green-mottled calcareous or dolomitic mudstones contain gypsum or alabaster nodules and veins. The older memoir describes about 15 m of exposed upper red marls in the coastal sections; this is not the full regional formation thickness. Arid continental mudflat and alluvial environments with evaporitic episodes provide the depositional context. More recent magnetic work examined a longer combined upper succession and recognises a possible substantial hiatus within the red mudstones, so the visible colour changes are not a guaranteed continuous time record.

Blue Anchor Formation

Grey-green mudstones and evaporitic beds — about 15 m at Lavernock. A sharp basal change introduces thinner-bedded grey-green mudstones. Gypsum occurs low in the formation, while argillaceous dolostone or limestone beds become more frequent upwards and reach about 20 cm thick. The reddish ‘pink band’ provides a conspicuous marker, but measurements differ between accounts: Hounslow and Andrews describe about 1.2 m, the GCR places it approximately 7 m above the base, and the BGS memoir gives 1.3 m at about one-third of the way up its section. These descriptions are retained with their sources rather than treated as one identical measured datum. Mudcracks, intraclasts and small burrows record changing saline-lake, mudflat and marginal-marine conditions. At the Point the formation base is taken beneath 0.2 m of green mudstone with gypsum nodules, resting on the highest red bed. Of twelve samples from cliffs north of Lavernock Point in the memoir’s study, only the sample 1.7 m below the top yielded a sparse miospore assemblage. The additional taxa in St Fagans borehole samples are not assigned to that coastal sample.

Upper erosion surface and disputed member terminology. At ST 188 681, the top dolomite has an eroded surface with U-shaped burrows reported up to 10 cm deep, and cracks, locally filled by younger sediment and vertebrate debris. Hounslow and Andrews assign the Lavernock Blue Anchor succession to the Rydon Member; the 1987 memoir did not identify a Williton Member and discussed whether the overlying bristovi limestones might be time-equivalent. The 2026 fish paper instead calls the substrate Williton Member. That disagreement is retained rather than resolved by stacking both member names into a new local sequence. The dinosaur-track locality south of Penarth pier is a different place and is not moved to Lavernock Point by a broad regional description.

PENARTH GROUP

Westbury Formation

Six local sedimentary cycles — about 6.6 m at Lavernock Point. Dark, fissile and commonly pyritic mudstones alternate with thin sandy or shelly limestones. Marine flooding, storm activity and repeated erosion concentrated vertebrate debris, while quieter intervals accumulated fine mud. The six upward-fining cycles recognised in the memoir describe the local succession; they are not six assumed globally synchronous events. The following fossil names retain the source’s historical identifications and qualifiers, rather than claiming a complete modern taxonomic revision.

Cycle 1 — the bristovi interval. A thin basal limestone–shale interval sharply overlies the Blue Anchor. Its richly coquinoidal development is absent or greatly reduced at Lavernock Point. At St Mary’s Well Bay, the maximum measured 1.13 m comprises 0.23 m of basal shale or conglomerate and 0.90 m of oyster limestone. That separate measurement includes Liostrea bristovi, Rhaetavicula contorta, a large Modiolus, historically identified Sphaerodus teeth and wood. It is not silently transferred to the Point or Penarth Head. Just north of the Point at ST 188 681, the source instead records 15–20 cm of dark shale with rare Rhaetavicula and Protocardia, capped by 5–10 cm of fine-grained dolomitic limestone. The cap is continuous southeastwards on the platform, but is deeply eroded towards the cliff and becomes nodular; both limestone and shale are rapidly cut out northwards by a minor non-sequence. At St Mary’s Well Bay the basal channels penetrate about 0.1 m into the Blue Anchor, and the 0.23 m basal shale includes 8–23 cm of mudstone conglomerate. The oyster limestone above has a lenticular shale parting, broken and commonly bored oysters in its upper part, and a slightly eroded silty top.

Cycle 2 — Storrie’s Fish Bed and overlying mudstone. The basal erosive, sandy and locally conglomeratic ossiferous bed cuts channels into the bristovi interval. Historical descriptions include quartz, quartzite, chert, limestone and mudstone pebbles up to about 5 cm and fish remains up to about 25 cm. The foreshore patch described as roughly 60 by 20 m was already much reduced by erosion in the 1987 account; those dimensions are not a promise of present exposure. Overlying mudstone contains scattered Eotrapezium, Protocardia rhaetica and Rhaetavicula contorta, alongside smaller fossils and pellets. A separate coprolitic horizon about 20 cm above the basal conglomerate is important in the recent fish study and must not be collapsed into the basal bed. The memoir reports sandstone containing up to 50% tooth, scale and bone fragments, a historical rock-composition observation rather than the unrecovered 2024 sample-abundance data. Its historical tooth roster includes Acrodus, Birgeria, rare Ceratodus, Dalatias, Hybodus, Lissodus, ‘Sargodon tomicus’, Saurichthys and ‘Sphaerodus’, with fin-spines of Hybodus and Nemacanthus monilifer, Gyroleptis scales and unidentified fish or reptile bones. Larger pieces may be broken, worn, sediment-filled and associated with pyrite. These names are an unrevised historical record and do not override the later fish-taxonomy discussion. Upwards the sandstone fines through siltstone into dark shale with pyritic lenses or nodules. Small ?neritoid ‘Natica oppelii’ may be preserved in fibrous calcite or pyrite, and three small Eolepas plates were recorded. Higher mudstone contains 0.5–1 mm rectangular, coprolite-like pellets compared historically with Bactryllium striolatum; additional inland cycle 2 and 4 records are not separate Point horizons.

Cycle 3 — erosive limestone lenses and thin bone-rich lamina. Basal lenses contain Eotrapezium and fish debris. About 0.6 m of shale and sandy, pyritic limestone above includes a bone-rich lamina approximately 1 cm thick. Load-cast lenses and incorporated mudstone fragments record disturbance of soft sediment. Fossils include Eotrapezium concentricum, E. cf. germari, Pleurophorus elongatus, rare Rhaetavicula, Eolepas and ostracods. Higher grey mudstone contains Rhaetavicula contorta, Lyriomyophoria postera, historical ‘Modiolus’ sodburiensis and ‘Natica’ oppelii; the latter becomes more prominent as bivalves decline. The associated limestones are individually up to 10 cm thick. Named marine ostracods include Metacytheropteron and Rhombocythere; rare Darwinula in cycle 3 has been interpreted as possible freshwater input, not proof that the entire interval was freshwater. The cycle ends with a rapid change into calcareous mudstone containing finely broken shell material.

Cycle 4 — calcareous silt and nodular limestone. The basal calcareous silt grades into nodular limestone. The fauna includes Chlamys valoniensis, Lyriomyophoria, ‘Modiolus’ sodburiensis, Placunopsis alpina, broken Rhaetavicula and echinoid debris; Tutcheria cloacina and ophiuroid remains also occur in this part of the succession. The abundant fauna persists into a calcareous mudstone bed about 1 m above the base, where Tutcheria cloacina is particularly common. Above this, about 0.4 m of hard dark mudstone has a sparse bivalve fauna. Fossil and Bactryllium comparisons from inland upper beds are not treated as additional coastal collections.

Cycle 5 — Lower Pecten Bed. Shelly limestone, locally with clasts and fibrous calcite, is overlain by grey mudstone rich in Chlamys valoniensis and Placunopsis alpina. Ophiuroid remains, occasional oysters and Modiolus occur. Higher levels contain Rhaetavicula, Eotrapezium and Lyriomyophoria, declining in abundance upwards. ‘Natica’ oppelii increases upwards to a level about 0.08 m below a ferruginous shell-fragment and silty sand layer about 1 cm thick.

Cycle 6 — Upper Pecten Bed. A thin shell-rich sandstone and calcareous mudstone lead into the limestone–shale interval known as the Upper Pecten Bed, with fibrous calcite, Chlamys valoniensis and Placunopsis alpina. Approximately 15 cm of overlying mudstone contains Lyriomyophoria, Protocardia, Tutcheria and Rhaetavicula. Much of the upper 0.6 m is nearly barren in the source account, but within its top 20 cm Protocardia reappears first, followed by Eotrapezium and Rhaetavicula on some bedding surfaces with ‘Natica’ oppelii. The Upper Pecten Bed’s fibrous-calcite layers reach about 10 mm. These are recorded bed associations, not a promise of equivalent abundance in current loose beach debris.

Additional source-chart fauna and limits. The memoir’s distribution figure records Orbiculoidea in cycle 5, Aplocoma (Ophiolepis) damesi in cycles 4–5, Dacryomya titei in cycle 4, and Modiolus hillanoides in cycle 5 and Langport beds. It shows Dimyopsis (Atreta) intusstriata from cycles 5–6 into Cotham and Langport strata. Cardinia records include an indeterminate species in cycle 3 and cf. regularis/other Cardinia in the upper units. These plotted ranges retain the chart’s historical taxonomy; question marks, sample marks and historical-only records are not converted into equally secure occurrences.

Sykes’s separate measured section at ST 188 682. Read from the top down, the published log records 1.7 m of shale greying upwards; 0.05 m limestone with fibrous calcite; 0.5 m black shale; 0.012 m limestone with fibrous calcite; approximately 1.2 m black shale; 0.1 m limestone; and 1.3 m black shale. Below these lies a 0.165 m internally divided bone-bed interval. Beneath it are 0.075 m black shale, an intermittent arenaceous limestone no more than 0.025 m thick with quartz, vertebrates and bivalves, and 1.0 m basal black shale with trace bone-bed patches; the basal pebble bed is locally absent. These are the dimensions of this independently logged section, not a relabelling of the six cycles.

The five sublayers within Sykes’s 0.165 m bone-bed interval. From bottom to top, sublayer a is 0.040 m of cemented pyritic mudstone with coarse grains and vertebrate remains; b is 0.015 m of impure dark-grey limestone; c is 0.065 m of sand-rich limestone, shell-rich below and richer in vertebrates, coprolites and quartz above; d is 0.020 m of black shale with scattered or patchy trace bone material; and e is 0.025 m of black shale with impure limestone above. These five thicknesses make up the stated total and must not be added to it again. No direct correlation is assumed with the approximately 5 cm basal conglomerate described in the 2026 fish paper.

Cotham Formation — Cotham Member of Lilstock Formation in the traditional scheme

Pale mudstones, erosion and deformation. Pale grey or green calcareous and silty mudstones overlie dark Westbury strata at a sharp, commonly channelled erosion surface. Lower beds have ripple, lenticular and wavy lamination. At Lavernock a deformed interval about 15 cm thick near the top of the lower part contains small faults and slumps; laterally variable deformation can also involve upper Westbury beds. A desiccation surface separates lower and upper Cotham, with sandstone-filled cracks penetrating underlying strata. Thin basal upper-Cotham ooidal sandstone carries ripple marks and cross or planar lamination. The BGS memoir specifically records cracks up to 8 cm wide and polygons up to 90 cm across at Lavernock. These are separate local observations from the St Mary’s Well Bay reference-section dimensions below. The broader 26 cm sandstone maximum is not assigned to this exact exposure, and Cotham Marble is not established in this district.

St Mary’s Well Bay Cotham reference section. Gallois’s separate Table 3 records, upwards from the sharp base, 0.16 m mudstone with lenticular silt and thin pyritic shell or fish debris; 0.24 m pale green-grey silty mudstone weathering in blocky or subconchoidal pieces; and 0.38–0.40 m interlaminated green-grey mudstone and grey siltstone. The upper part begins with 0.23 m sandstone and siltstone with stacked ripples and basal cracks up to 30 mm wide and 0.4 m deep, followed by 0.17 m fine calcareous sandstone with wavy bedding, 0.13 m with stacked ripples, and 0.18–0.20 m sandstone or calcarenite with pyritic shell debris, limestone lenses up to 0.06 m and a mineralised upper surface. The table includes only 0.50 m of underlying upper Westbury mudstone, not its full formation thickness. These detailed measurements belong to St Mary’s Well Bay, not an identical log at Lavernock Point.

White Lias Formation — lower Langport Member in the traditional scheme

Thin pale limestone and locality-dependent thickness. Porcellanous micritic limestone may form two beds separated by mudstone, with irregular mineralised surfaces. Gallois gives 0.20–0.30 m at Lavernock Point, compared with 0.30–0.40 m at St Mary’s Well Bay; the GCR describes no more than about 0.35 m locally. The latter reference section contains three limestone beds individually 0.09–0.20 m thick, separated by 10–50 mm mudstones. A recent generalised 0.65 m statement differs from these direct local measurements; 0.65 m is the older memoir’s Porthkerry figure and is not substituted here. Oysters, Modiolus, Dimyopsis/Atreta and recrystallised small coral fragments occur. The memoir’s named Montlivaltia rhaetica record is specifically Penarth Head, not automatically Lavernock Point.

Watchet Mudstone Formation — upper Langport Member in the traditional scheme

Calcareous silty mudstone and shell concentrations. Pale to medium-grey, commonly blocky mudstone is locally bioturbated, with shell-rich levels and occasional thin limestone or sandstone. The GCR’s local discussion gives about 2.2 m; Gallois gives a broader coastal range of 2.2–2.5 m. His St Mary’s Well Bay table describes 2.15 m of upper calcareous mudstone with Liostrea and Modiolus, burrowed below, above a 2–5 cm shell-rich basal mudstone, for a reported approximately 2.20 m total. The basal interval passes laterally to dense shelly limestone at Lavernock. Bivalves and Chondrites-type burrows support marine deposition. The 4.8 m St Fagans borehole thickness is not this coastal section.

Upper Penarth source-chart records. The historical distribution chart adds ‘Arca’ cf. pullus, Liostrea hisingeri, Pleuromya and Plicatula in Langport strata, with Meleagrinella fallax and Modiolus minimus/indeterminate Modiolus in the upper units. Gervillia praecursor is recorded in Cotham and Langport beds, with less secure lower indications. The plotted Pteromya record and several upper ranges carry uncertainty; Plagiostoma valoniensis is a historical Langport report rather than an equally secure new sample. Diademopsid fragments, barnacle Eolepas, small bivalves and fish/reptile fragments span selected upper intervals, but none is treated as continuously abundant through every bed.

Microfossils and environmental change in the memoir. At St Mary’s Well Bay the bristovi interval’s palynomorphs are dominated by miospores, particularly Ovalipollis pseudoalatus and Classopollis, with sparse Rhaetogonyaulax rhaetica and acritarchs. The local upper Westbury assemblages become dominated by Rhaetogonyaulax rhaetica, with Cymatiosphaera, sporadic Veryhachium and tasmanaceans; foraminiferal test linings occur high in the succession. Lower Cotham assemblages below the desiccation surface retain the marine dinoflagellate dominance, whereas upper Cotham is dominated by Gliscopollis meyeriana and has few organic-walled marine microplankton. White Lias samples contain sparse miospores including Gliscopollis, Classopollis and Deltoidospora. In the Watchet beds, Classopollis, Gliscopollis, Quadraeculina anellaeformis and Kraeuselisporites reissingeri accompany mainly Micrhystridium-type acritarchs. These are source-described assemblage changes rather than a newly digitised abundance matrix; environmental changes may control them, so they do not by themselves fix the system boundary.

Nomenclature crosswalk and the system boundary. In the traditional scheme, Cotham and Langport are members of the Lilstock Formation. Gallois separates Cotham, White Lias and Watchet formations, with the old Langport interval comprising White Lias plus Watchet. These overlapping names must not be counted as five additional superposed units. The interpretation of the Triassic–Jurassic boundary has also changed: an ammonite and supporting correlation place it much lower than the traditional first Psiloceras planorbis, in the White Lias, with continuing uncertainty over its precise relationship to the global marker. Neither the Paper Shales nor the Blue Lias lithological base automatically equals that boundary.

LIAS GROUP

Blue Lias Formation

St Mary’s Well Bay Member

Basal Paper Shales. Approximately 0.20 m of well-laminated silty mudstone marks the lithological Blue Lias base in the GCR account. Gallois’s independently measured St Mary’s Well Bay reference section gives 0.32 m of interlaminated, organic-rich fissile mudstone beneath a 0.09 m argillaceous blue-grey limestone. These are separate measured accounts; their centimetre-scale values should not be merged into one universal thickness.

Bull Cliff Bed — historical Bull Cliff Member, about 3.1–3.6 m. Mainly tabular limestone with subordinate mudstone contains abundant Liostrea hisingeri, Modiolus minimus and disarticulated echinoids, including records of Diademopsis serialis and Eodiadema bechei. The top is taken at the base of the lowest conspicuously nodular limestone, the Dual Bed or Plagiostoma Bed. The Bull Cliff Bed lies within the current St Mary’s Well Bay Member and is not an extra member to add beneath its complete thickness.

Higher St Mary’s Well Bay beds and total thickness. About 13.1 m above the historical Bull Cliff subdivision contains nodular and tabular limestone alternating with calcareous mudstone. The combined member, called a formation in the older memoir, is about 16–18 m thick; the basal subdivision must not be added twice. Above the Dual Bed, the fauna broadens to include Plagiostoma giganteum, Pinna, and the additional bivalves Camptonectes, Chlamys, Oxytoma and Terquemia, together with the crinoid Isocrinus psilonoti and echinoid Miocidaris lobatum. The first Psiloceras planorbis is recorded about 1.4 m above the Dual Bed. The memoir’s designated coastal type section measures 16.2 m. Its more usual argillaceous limestone beds are approximately 5 cm to 0.3 m thick, with mudstone ranging from partings to 0.7 m; parallel-sided, undulating and nodular beds intergrade, and burrowing and diagenesis make many contacts gradational. Laminated, often bituminous and largely unburrowed rocks form a distinct facies at the named marker intervals rather than occurring throughout. The GCR records Pinna hartmanni at a few levels without establishing a new precise bed assignment here, and assigns the uppermost 2.7 m of the member to the Liasicus Zone.

Ammonite and laminated-bed markers. In Waters and Lawrence’s numbering, bed 30 contains an early indeterminate psiloceratid and bed 32 flattened Psiloceras planorbis. Beds 39–41 include the conspicuous Planorbis Mudstones, about 0.65 m thick and roughly 7 m above the Blue Lias base. The Lower Laminated Beds, about 0.7 m, occur approximately 1 m higher. The Upper Laminated Beds include a distinctive 0.08 m laminated limestone in about 0.9 m of fissile strata, with another thin limestone above; the GCR figure marks beds 58–59 in this interval. These are named, locally supported horizons rather than a complete invented description for every intervening bed. The memoir places the Lower Laminated Beds about 8–9 m above the formation base and the Upper Laminated Beds about 10–11 m above it. In the St Mary’s Well Bay–Lavernock cliff section, the 0.08 m bed 59 limestone is overlain by 0.13 m of laminated shale before the next thin limestone; measurements from Barry or St Fagans are not substituted for this local interval. The GCR describes the Upper Laminated Beds as almost 2.5 m above the Lower Laminated Beds; this relative separation belongs to that account rather than replacing every independently measured bed height.

Higher ammonites and member top. Caloceras begins around bed 52; Waehneroceras appears at bed 77, indicating Liasicus Zone strata. Bed 86 is the top limestone at the member boundary. These are Waters and Lawrence bed numbers; bracketed numbers in the conservation-review figure refer to Trueman’s separate numbering. They must not be interchanged with the dinosaur paper’s independent beds 7 and 9.

Lavernock Shales Member

Mudstone-dominated Liasicus interval — about 12 m. Grey calcareous, fossiliferous and bioturbated mudstone contains relatively few nodular limestones. Recorded fossils include Cardinia listeri, Waehneroceras portlocki and Psilophyllites hagenowi. The boundary is a practical lithological division rather than an instantaneous environmental change. Trueman’s detailed upper log combined inland exposures, and the conservation review warns of possible errors in correlation and identification; it cannot be presented as a fully verified modern bed-by-bed cliff log. The GCR places the top at the base of Waters and Lawrence’s bed 87, with the member below bounded at the top of bed 86.

Porthkerry Member

Lower exposed part at St Mary’s Well Bay — about 10 m. Alternating limestone and shale form the upper cliff. Much of the interval belongs to the upper Liasicus Zone; a historical Schlotheimia aff. thalassica record near the top suggests Angulata Zone strata. This is only the lower exposed part of the member, not its full regional thickness or a readily accessible foreshore succession.

Dinosaur provenance and specimen inventory. The associated partial skeleton of Dracoraptor hanigani was recovered in fallen blocks in March 2014 near ST 187 681. Lithology and thickness suggested the describing paper’s bed 7 or 9 near its 6 m datum, about 3 m below its first Psiloceras planorbis; the horizon is inferred, not an observed in-situ extraction. The holotype catalogue NMW2015.5G.1–11 includes skull blocks .1a/b; hind-limb, pelvic and caudal material .2a/b; forearm, hand and fibula .3; right foot .4; caudal material .5; a loose cervical vertebra .6; tibial fragment .7; possible rib fragment .8; and casts .9–11. The later left-foot blocks NMW2015.10G.1a/b were recovered on 20 July 2015. Casts are not extra original bones and the foot is not a second dinosaur. The paper interpreted a roughly 40%-represented small basal neotheropod, without requiring an enduring global ‘oldest dinosaur’ claim.

The White Lias ammonite evidence. The holotype of Neophyllites lavernockensis, NMW.83.22G.1459, is a 20.8 mm pyritic internal cast from fallen material at ST 181 681, called Lavernock Point by its author. Adhering matrix was compared by X-ray diffraction with upper White Lias bed WL1, supporting an inferred horizon. A second, very worn ammonite was observed in situ on the upper surface of WL1, but was not securely identified and has no supplied accession. The accession prefix is not a discovery date, and the two records do not have identical certainty or collecting circumstances.

Historical figured Lavernock ammonite. Trueman’s Plate 9A and its explanation identify Schlotheimia cf. hagenowi from “near Lavernock Station, Glam.”, with the plate explanation giving the historical “liasicus sub-zone”. This is an inland locality in the wider Lavernock area, not a proved coastal bed. His two measurement tables describe this provisional taxon’s dimensions and growth, and text Figure 69 illustrates its sutures despite being placed beside the following Arnioceras discussion. The figure must not be reassigned to that genus. No museum accession is supplied in the source, and the old name is not silently equated with a modern generic assignment. Plate 9B, showing Arnioceras cf. spirale, belongs to Summerhouse Point and is not a Lavernock specimen. Separately, a footnote places this material in the lower part of the historical Angulata Zone at Lavernock, with other Schlotheimia. Both historical horizon statements are retained rather than silently reconciled; neither supplies an exact modern coastal bed number.

Recent vertebrate work and its limits. The jaw element NMW2023.1G.1, found and prepared by Jonathan Bow in 2010, comes from coprolitic shale about 20 cm above the basal conglomerate. Its 2026 study supports Saurichthys sp. separate from Birgeria acuminata, rather than combining their teeth under Severnichthys; Saurichthys longidens remains a cautious species-level attribution. The source’s caption calls the element a neotype while the systematic text calls it referred material, so no type-status claim is made here. The 2024 re-study of the basal assemblage reports bony-fish tooth dominance, abundant Sargodon, relatively few Lissodus and transport bias, but unrecovered full count tables and accession lists are not turned into numerical proportions or extra specimens. Historical museum ammonites include uncertain-provenance Alsatites liasicus and a supposed Schlotheimia gallica reidentified as Waehneroceras portlocki; no unsupplied catalogue numbers or exact bed assignments are invented. The 2026 account describes about 0.5 m of black shale and reports rare placodont osteoderms from the coprolitic horizon, without supplying an accession for those pieces. This remains an attributed occurrence report, not a reconstructed specimen roster. The source describes the horizon as exposed only at extremely low spring tides; that does not make it a recommended or reliably safe collecting destination.

References. Waters, R.A. and Lawrence, D.J.D. (1987), Geology of the country around Cardiff, Chapters 6–7; Benton, M.J., Cook, E. and Turner, P. (2002), Permian and Triassic Red Beds and the Penarth Group of Great Britain, Lavernock account; Simms, M.J. and colleagues (2004), British Lower Jurassic Stratigraphy, Lavernock–St Mary’s Well Bay; Sykes, J.H. (1977), local Rhaetic bone-bed sections; Gallois, R.W. (2009), Severn Estuary Penarth Group succession; Martill, D.M. and colleagues (2016), original Dracoraptor hanigani description; Hodges, P. (online 2020, print 2021), Neophyllites lavernockensis; Hounslow, M.W. and Andrews, J.E. (2024), magnetostratigraphic study; Evans and colleagues (2024), Lavernock vertebrate assemblage; Quinn and colleagues (2026), Saurichthys revision; current BGS Lexicon entries.