A reconsideration of the radiocarbon dating of the Marine Isotope Stage 3 fauna from southern Ireland

Abstract

With the improvements in the techniques of radiocarbon dating since the 1990s and the pretreatment of bone samples, it has become apparent that some of the radiocarbon dates from Irish caves such as Castlepook Cave may not be as accurate as previously determined. The faunal remains and sediments within Castlepook Cave are important as this cave is one of only two caves in Ireland in which both pre‐ and post‐Last Glacial Maximum sediments containing faunal remains are found. In this study, samples of identified bones were re‐dated from this cave as well as two others (Foley and Shandon caves) from the same region in the south‐southeast of Ireland. The new dates from Castlepook Cave disclosed results that were significantly older by between c. 5000 and 12 000 radiocarbon years. This was not as apparent in dates obtained from Foley and Shandon caves, where the new dates were older by c. 4000 radiocarbon years on average. The results imply a much older presence of certain mammals during MIS 3 in Ireland and suggest that certain species, notably giant deer and spotted hyaena, may have become locally extirpated before the Last Glacial Maximum, around 40 cal. ka BP.

Next-generation phylogeography resolves post-glacial colonization patterns in a widespread carnivore, the red fox (Vulpes vulpes), in Europe

“…Given that models of glaciation/de-glaciation patterns are reliant on secure and accurate fossil data, the island may have hosted a larger mammalian community in the early post-glacial period and this may have included the red fox also. While humans were still likely an important factor in determining later faunal assemblages on Ireland (Carden et al, 2012;Frantz et al, 2014), the early post-glacial period clearly warrants further investigation on the island based on the results presented here and newly available fossil data (Dowd & Carden, 2016;Carden et al, 2020).…”

“…mountain hare Lepus timidus and arctic lemming Dicrostonyx torquatus; Woodman et al, 1997) were also present in the early post-glacial period. A recent re-assessment of several Irish mammalian fossils has pushed several species (reindeer Rangifer tarandus, grey wolf Canis lupus and woolly mammoth Mammathus primigenius) to the LGM/post-glacial boundary (Carden et al, 2020). Given that models of glaciation/de-glaciation patterns are reliant on secure and accurate fossil data, the island may have hosted a larger mammalian community in the early post-glacial period and this may have included the red fox also.…”

“…This uncertainty and lack of resolution in phylogeographic structure outside the 'traditional' (and wellestablished) refugia means that inferring post-glacial colonization patterns of previously glaciated regions during the LGM is challenging with more limited genetic marker sets. This is particularly evident in the British Isles and Scandinavia where these regions present differing problems in terms of how and when contemporary populations of terrestrial species reached these areas in post-glacial periods (Carden et al, 2012(Carden et al, , 2020Herman et al, 2014).…”

“…The island of Ireland has long presented a biogeographical quandary in terms of how and when terrestrial species colonized it (Carden et al, 2012(Carden et al, , 2020McDevitt et al, 2011). The area's latitude means that it was covered almost entirely by the ice sheet during the LGM and it didn't become an island until approximately 15,000 years ago (almost twice as long as Britain; Edwards & Brooks, 2008).…”

“…Indeed, natural colonization of other species (e.g. stoat Mustela erminea) have been proposed over post-glacial land bridges (Martínková, McDonald, & Searle, 2007) and a recent reevaluation of fossil dates has now placed multiple mammalian species on the island close to the end of the LGM period (Carden et al, 2020). Therefore, a more thorough investigation of the red fox's colonization history on the island has implications beyond this species only.…”