FOSSIL SITES IN IRELAND - Chapter 1 - Introduction

Contents - Fossils sites in Ireland

Section 1-1 - Fossil collecting in Ireland
Section 1-2 - Where are the dinosaurs?
Section 1-3 - The good news

Section 2-1 - Precambrian/Cambrian
Section 2-2 - Ordovician
Section 2-3 - Silurian
Section 2-4 - Devonian
Section 2-5 - Carboniferous/Mississippian
Section 2-6 - Carboniferous/Pennsylvanian

Chapter 3 - Fossil sites in Ireland
Section 3-4 - County Sligo - Streedagh Point - Mississippian 

Resources

Chapter 1 - Introduction - Fossil sites in Ireland

by Jutta Kruse, version April 2025

This is an illustrated overview of some Irish fossil sites. The information is arranged in chapters and sections. The short citations in the text refer to the sources detailed in the chapter Resources.

If you spot any errors or omissions, please let me know, Jutta at info@fossils.ie

Images ⓒ Jutta Kruse unless otherwise noted.

Section 1-1 - Fossil collecting in Ireland

Fig. 1 - Ancient and new ripples and trace fossils at Seafield beach, County Clare.

Please leave fossils in Ireland where you find them. Search, find, identify, photograph and post them online, but do not specify the exact location where they were found to protect them from damage.

In general, the extraction, collection and sale of fossils from Ireland is not permitted. Additional regulations apply to areas that enjoy special protection, for example European Geoparks, Special Areas of Conservation under the EU Fauna-Flora-Habitat Directive and areas identified under the Irish Geological Heritage Programme (GSI, County Geological Site Audits), (Burren Geopark, Fossil Collecting Policy), (European Geoparks Charter).

Section 1-2 - Where are the dinosaurs?

To put it briefly: it's uncertain. 

The classic rocks that could contain dinosaur fossils are largely missing (Holland & Sanders, 2009, pp 311-332). The southern part of the Irish island has hardly any rocks from the Triassic, Jurassic or Cretaceous. Almost all rocks are older than 250 million years, the younger ones are absent.

Only two dinosaur bones (Scelidosaurus and Megalosaurus) have been found, both in county Antrim in Northern Ireland (United Kingdom), where the relevant rocks are preserved under protective basalt [Fig. 1.1] (Website: National History Museum UK) (Video: Simms, Dinosaurs). However, the proximal femur which had been tentatively assigned to the genus Scelidosaurus (Simms et al., 2021) has been re-evalued and may not belong to this genus (Satchell, 2024). 

Even this part of Ireland, the rocks consist of either desert or marine sediments, which naturally contain few dinosaur fossils. Mosasaur fossils have been found in the marine deposits of the Cretaceous of Northern Ireland, and ichthyosaurs and plesiosaurs in those of the Jurassic (Video: Simms, Dinosaurs).

Fig. 1.1 - Dr Mike Simms of the National Museums Northern Ireland, with a theropod tibia (left) and a Scelidosaurus femur (right), both from the Jurassic of county Antrim. (Image © National Museums NI. Used with permission of the University of Portsmouth)


Section 1-3 - The good news

Fortunately, many fossils from the Palaeozoic era are preserved in Ireland.

For example, Cambrian rocks are found in Counties Wicklow and Wexford; Ordovician rocks in Counties Mayo, Wicklow, Waterford, Dublin and Down; Silurian rocks in Counties Kerry, Galway, Offaly, Tipperary and Mayo; Devonian rocks in Counties Waterford, Wexford, Cork and Kerry; and Mississippian rocks in almost all counties south of Galway. Pennsylvanian rocks are particularly well represented in counties Clare, Kerry and Limerick (Sleeman et al., 2004). 

The few coal deposits containing fossils mostly come from the Carboniferous stages of the Namurian (more on the Namurian below), in counties Leitrim, Antrim and Tyrone (United Kingdom) and early Westphalian in counties Kilkenny, Carlow and Tipperary (Sleeman et al., 2004). The geological map [Fig. 1.2] shows the diversity of rocks on the island.

Fig. 1.2 - Ireland - Geological map 1:500,000 (GSI, 2006).

Larger pdf file 8.3 MB (GSI, 2006).