Fermanagh Pools, Cork Reindeer

Dateline

The label 31,398 BCE gives a useful point of orientation, but it cannot describe a year in the ordinary historical sense. No people in Ireland then used a calendar from which such a date could be counted, and the evidence available to archaeologists and Quaternary scientists cannot be resolved to a particular season, let alone a day or year. In radiocarbon convention this notional date falls roughly 33,350 years before AD 1950, during Marine Isotope Stage 3, a long, climatically unstable part of the last glacial cycle. The responsible question is therefore not “what happened in 31,398 BCE?” but what securely dated deposits can tell us about Ireland during the broad interval around it.

A Cold Interval, Not a Single Year

For Ireland, the period belongs to the Middle Midlandian, the local name often used for part of the Late Pleistocene glaciation. It was neither a simple age of permanent ice nor a settled countryside awaiting later history. Climate in the North Atlantic region swung sharply between colder and relatively milder phases. Ice expanded and contracted; sea levels, coastlines and animal routes altered; and later glaciers repeatedly eroded or buried the evidence. That destruction is a major reason why Ireland’s deep prehistory is known from a small number of unusually fortunate survival sites rather than from a continuous archaeological record.

The most useful chronological language is consequently expressed in ranges. The organic deposit at Derryvree, near Maguiresbridge in County Fermanagh, produced a conventional radiocarbon age of 30,500 +1,170/−1,030 radiocarbon years BP. Calibration converts a radiocarbon measurement into a calendar-age probability range, rather than a single exact answer. Published discussion places the Derryvree evidence broadly within approximately 36,900–31,700 calibrated years BP, or about 34,950–29,750 BCE. The nominal date considered here lies inside that wide span. It does not identify one moment in the life of the wetland; it permits the deposit to illuminate the environmental world of this period.

The Derryvree Evidence

Derryvree is important because roadworks in 1969 exposed a section through a drumlin, one of the streamlined hills fashioned by glacier ice. Beneath the modern surface lay two distinct tills: unsorted material deposited by glaciers. Between them was a sequence of freshwater silts, fine sands and organic-rich layers. Its order is clear even where its calendar age is broad. An earlier ice advance laid down the lower till. Afterwards, standing or slow-moving freshwater and wet ground allowed sediments, plants and insects to accumulate. A later glacier then overrode and sealed the deposit beneath another till.

That sequence is direct evidence that this part of Fermanagh experienced a non-glacial interval between two episodes of ice deposition. The biological remains indicate a cold, open environment rather than forest. Freshwater mosses and sedges, together with an insect fauna of northern, cold-climate character, point to tundra-like wetland and periglacial ground: land subject to intense freezing, thawing and frost action at the margin of shallow pools and waterlogged hollows. The deposit has often been described as tundra or muskeg, but those terms are interpretative summaries of a varied local landscape. It was not a uniform, featureless plain.

Nearby sites reinforce the value of this regional record while also warning against overconfidence. Inter-till organic deposits at Hollymount, also near Maguiresbridge, and at Greenagho near Belcoo preserve further indications of cold, non-glacial conditions in Fermanagh during parts of the Middle Midlandian. Their dating and correlation are not equally secure. Greenagho’s radiocarbon result, for example, has been treated cautiously. Together, the sites show that north-western Ireland retained or regained patches of ice-free terrain during the long last glaciation. They do not demonstrate that the whole island was simultaneously clear of ice, nor do they allow a precise map to be drawn for 31,398 BCE.

Ice, Water and Changing Ground

The wider glacial setting remains actively researched. Recent reconstructions of the British–Irish Ice Sheet begin their detailed time slices at about 31,000 years ago because older constraints are sparse and uncertain. At that stage ice was building in the region, including centres of accumulation in Northern Ireland in some reconstructions, but its exact limits remain debated. The much more extensive Last Glacial Maximum lay ahead, with the ice sheet reaching its greatest late-glacial volume and extent after this earlier phase. Ireland’s landscape was therefore dynamic: a place of advancing ice in some districts, exposed cold ground in others, and environments vulnerable to being removed by later erosion.

This uncertainty matters for the question of movement. Lower global sea level did not automatically create a permanent, simple land bridge from continental Europe to Ireland. The geography of the Irish Sea was shaped by sea level, local crustal movements caused by the weight of ice, shifting shorelines and the presence or absence of glacier ice. Animals and perhaps people could reach Ireland only through changing routes and conditions, not across a timeless bridge. The fossil record proves that mammals did arrive during the Late Pleistocene; it does not settle exactly how every species, or every human visitor, travelled.

Castlepook’s Faunal Archive

South-west of Derryvree, Castlepook Cave near Doneraile in north County Cork provides a different kind of evidence. Its deposits and old excavation collections form Ireland’s most important known archive of pre-Last Glacial Maximum cave fauna. Re-dating has shown that some animal remains from Castlepook belong to Marine Isotope Stage 3, substantially earlier than earlier dating programmes suggested. The cave has yielded or been associated with remains of cold-stage animals including reindeer, spotted hyaena, mammoth, brown bear, wolf, Arctic fox, lemmings and mountain hare, as well as giant deer.

Those names should not be converted into a single illustrated scene. Cave assemblages accumulate over long periods and through several processes: carnivores carry in prey, animals die naturally, water shifts bones, sediment enters through fissures, and nineteenth- and early twentieth-century digging can disturb context. Re-dated material establishes that Ireland supported, or was visited by, a varied cold-stage fauna across a substantial span before the glacial maximum. It cannot prove that every listed species lived beside one another, or at Castlepook, at precisely the notional date in this article.

Nevertheless, the broad picture is striking. Reindeer were well suited to open cold country, while hyaena remains show that predators also used the Irish landscape. A cave could be a den, a refuge, a trap, a place into which water and sediment washed bones, or several of these at different times. Castlepook is therefore more than a catalogue of extinct animals. It shows why the Irish Pleistocene record needs taphonomic care: bones reveal real animal lives, but their final resting place may not be where those lives ended.

A Reindeer Femur and Human Possibility

One Castlepook reindeer femur has particular importance. It has been reported as carrying a deep mark consistent with butchery by a stone tool, and its radiocarbon age has been publicised as around 33,000 years ago. If the mark is confirmed as anthropogenic and was made when the bone was fresh, it would be evidence that a human being processed a reindeer in Ireland during the Upper Palaeolithic, tens of millennia before the previously accepted late-glacial traces of people on the island.

The distinction between evidence and interpretation is essential. The dated bone and the mark upon it are physical observations. A visiting hunting party, a seasonal journey following reindeer, or a crossing from Britain are possible interpretations. None is demonstrated by the femur alone. No securely associated hearth, stone-tool assemblage, dwelling floor, burial, human remains or repeated campsite of this age has yet established a permanent human community in Ireland. Recent work at Castlepook has located surviving Pleistocene sediments, but has also underlined the difficulty of separating ancient deposits from later disturbance and modern material.

No Kingdoms, No Farms

There is no evidence for Irish political affairs, diplomacy, warfare, named communities, law or leaders around this date. Nor is there Irish evidence for agriculture, livestock, pottery, monuments, writing, formal learning, metalworking or a trade system. It would be misleading to supply such institutions merely because Upper Palaeolithic groups elsewhere in Europe possessed elaborate technologies, social ties and cultural practices. Continental comparisons offer a plausible human context, not proof that equivalent activities occurred in Ireland.

If people were present, the evidence presently supports only a fleeting possibility of hunter-gatherer activity in a demanding environment. Their immediate economy would have depended on the practical use of animal and plant resources, but no Irish site of this age permits the reconstruction of meals, shelters, clothing, ritual or social organisation. Reindeer would have been a potentially valuable source of meat, hide, bone and antler; that is a general inference from hunter-gatherer lifeways, not a demonstrated Castlepook economy.

The clearest history around 31,398 BCE is thus environmental. Fermanagh’s sealed freshwater deposits preserve cold wetland life between ice advances. Castlepook preserves the fragmentary remains of animals that entered an Irish glacial landscape, perhaps alongside an exceptionally early human trace. Both places stress the same lesson: Ireland was not outside the Ice Age world, but its evidence has survived only in pieces. Those pieces are enough to reveal changing waters, tundra vegetation, large mammals and uncertain human contact. They are not enough to turn one modern calendar year into an event.