This is a list of fossiliferous stratigraphic units in Wales.

Group or Formation	Period	Notes
Aber Mawr Shale	Ordovician
Afon Ffinnant Formation	Ordovician
Allt Ddu Formation	Ordovician
Aran Volcanic Group/Llyn y Gafr Formation	Ordovician
Bala Group/Rhiwlas Formation	Ordovician
Black Rock Limestone	Carboniferous
Blaencediw Formation	Ordovician
Bod Deiniol Formation	Ordovician
Bodeidda Mudstone	Ordovician
Bronydd Formation	Silurian
Bryn Siltstone Formation	Ordovician
Builth Volcanic	Ordovician
Camnant Mudstone	Ordovician
Carmarthen Formation	Ordovician
Carmarthen Group/Afon Ffinnant Formation	Ordovician
Carnedd Iago Formation	Ordovician
Crychan Formation	Silurian
Cwm Felin Boeth Formation	Ordovician
Cymerig Limestone	Ordovician
CyrnFormation	Ordovician
Dolhir Formation	Ordovician
Dyserth Quarry Limestone	Carboniferous
Elton Beds	Silurian
Ffestiniog Flag Formation	Cambrian
Ffestiniog Flags	Cambrian
Foel Formation	Carboniferous
GelliFormation	Ordovician
Glyn Formation	Ordovician
Glyn Gower Formation	Ordovician
GraigFormation	Ordovician
Gronant Formation	Carboniferous
Haverford Formation	Ordovician
Haverford Mudstone	Silurian
Hells Mouth Grits	Cambrian
High Tor Limestone	Carboniferous
Hirnant Limestone	Ordovician
Hope Shale	Ordovician
Hughley Shale	Silurian
Hunts Bay Oolite Formation	Carboniferous
Leete Limestone	Carboniferous
Llanarmon Limestone	Carboniferous
Llandudno Pier Dolomite Formation	Carboniferous
Llanelly Formation	Carboniferous
Llanfallteg Formation	Ordovician
Llanfawr Mudstone	Ordovician
Llwyn Formation	Carboniferous
Lower Flaxley Beds	Silurian
Lower Longhope Beds	Silurian
Lower Old Red Sandstone Group/Downtonian Formation	Silurian
Ludlow Series Group/Whitcliffe Formation	Silurian
Mawddach Group/DolFormation	Ordovician
May Hill Sandstone Formation	Silurian
Mercia Mudstone	Triassic
Middle Elton Formation	Silurian
Milford Haven Formation	Silurian
Moel Hiraddug Limestone	Carboniferous
Nant Ffrancon Formation	Ordovician
Nant Hir Formation	Ordovician
Nant Hir Group/Derfel Limestone	Ordovician
Ogof Hen Formation	Ordovician
Onny Shale	Ordovician
PenFormation	Silurian
Plas Uchaf Formation	Ordovician
Pont y Fenni Formation	Ordovician
Pontyfenni Formation	Ordovician
Quartz Conglomerate	Devonian
Senni bed Formation	Devonian
Senni Beds	Devonian
Sholeshook Limestone	Ordovician
Slade and Redhill Mudstone	Ordovician
Spring Quarry Limestone	Carboniferous
St. Maughan's Formation	Devonian
Sully Beds	Triassic
Sutton Formation	Jurassic
Sutton stone Formation	Jurassic
Trefawr Formation	Silurian
Treiorwerth Formation	Ordovician
TyFormation	Silurian
Upper Blaisdon Beds	Silurian
Upper Flaxley Beds	Silurian
Upper Longhope Beds	Silurian
Wenallt Formation	Ordovician
Wenlock Shale	Silurian
Wilsonia Shales Formation	Silurian
Woolhope Limestone	Silurian

References

Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.

v t e Geology of Wales
Counties	Anglesey Carmarthenshire Ceredigion (Cardiganshire) Monmouthshire Pembrokeshire Powys
National parks	Brecon Beacons (Bannau Brycheiniog) Pembrokeshire Coast Snowdonia (Eryri)
Other areas	Gower Peninsula South Wales
Other related topics	Mining in Wales
Geology Wales

Geography of Wales

Geography of the United Kingdom

Physical

Bays
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Border with England
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- Wat's Dyke
Canals
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Desert of Wales
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Extreme points
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Geology
- fossiliferous stratigraphic units
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Environment

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Administrative

Subdivisions	Local government history Cantref Commote Marches lords law Hundreds Historic counties by area 1831 1891 1844–1974 exclaves by population in 1971 Poor law unions Local districts 1848–1894 1894–95 1896–1974 UDs RDs 1973 Preserved counties districts Principal areas list Communities list Electoral wards Built-up areas Regions for economy
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Toponymy	General forms of place-names Caer Llan Pil Welsh Place-Name Society In other countries in the United States Standardised Welsh

Social

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Demography
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Anglo–Welsh relations
Y Fro Gymraeg (Welsh-speaking areas)
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Other

v t e Fossiliferous stratigraphic units of the countries and dependencies of Europe
Sovereign states	Albania Andorra Armenia¹ Austria Azerbaijan¹ Belarus Belgium Bosnia and Herzegovina Bulgaria Croatia Cyprus¹ Czech Republic Denmark Estonia Finland France Georgia¹ Germany Greece Hungary Iceland Ireland Italy Kazakhstan¹ Latvia Liechtenstein Lithuania Luxembourg Macedonia Malta Moldova Monaco Montenegro Netherlands Norway Poland Portugal Romania Russia¹ San Marino Serbia Slovakia Slovenia Spain Sweden Switzerland Turkey¹ Ukraine United Kingdom England Northern Ireland Scotland Wales Vatican City
States with limited recognition	Abkhazia¹ Kosovo Nagorno-Karabakh¹ Northern Cyprus¹ South Ossetia¹ Transnistria
Dependencies and other territories	Faroe Islands Denmark Åland Islands Finland Svalbard Norway Akrotiri and Dhekelia¹ / Gibraltar / Guernsey / Isle of Man / Jersey United Kingdom
¹ Can also be considered as being in Asia.

See also

References