Late Pleistocene remains of giant deer (Megaloceros giganteus Blumenbach) in Scandinavia: chronology and environment

摘要

This article presents new data on the Late Pleistocene giant deer, Megaloceros giganteus (Blumenbach), describing its distribution in time and space, geographical and sexual variation and general biology. Twenty-three south Scandinavian fossils found in situ in lacustrine sediments or redeposited in glaciofluvial material form the basis of this investigation. Fourteen C-14 dates show that the giant deer inhabited southern Scandinavia in the ice-free late Middle Weichselian from c. 40000 to 28000 BP (the Sandnes Interstadial) and again in the Late Weichselian from c. 12000 to 10700 BP (Older Dryas, Allerod and early Younger Dryas Chronozones), corresponding to a calibrated range from c. 14300 to 12400 cal. yr BP. Osteometric analyses show that the Scandinavian giant deer belonged to the upper size range of the lateglacial Irish population and that a marked sexual dimorphism existed, the males being 10-11% larger than the females. Investigations furthermore point at an antler cycle similar to that among extant northern cervids, and subsequently at a rutting season in autumn. The skeletal remains also prove the occurrence of twin delivery and the possibility of reaching an ontogenetic age of at least 23 years. During both occurrences the Scandinavian giant deer population was part of the northernmost distribution of the species in Europe and the palaeogeographical settings and palaeoenvironmental conditions of the two periods show striking similarities. Clearly, the giant deer were able to colonize and survive in a landscape dominated by grasses and sedges with scattered shrubs and dwarf shrubs. They came as close as 200-250 km to the ice front and their distribution included coastal areas along a cold sea with drifting icebergs. They were present in the area at least from March until November. However, the pure arctic conditions created during the early phase of the Younger Dryas event led to a new local extinction around 10700 C-14 yr BP. This was the beginning of a total Eurasian extinction which, at least in Europe, was completed before the Pleistocene/Holocene transition.