Irish Elk
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| Irish Elk Conservation status: Extinct (5000BC) | ||||||||||||||
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 Skeleton at the National Museum of Natural History | ||||||||||||||
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| Megaloceros giganteus (Blumenbach, 1799) |
The Irish Elk (Megaloceros giganteus) is an extinct deer that lived in Europe during the Pliocene, Pleistocene, and Holocene epochs. It is famous for its formidable size (about two meters at the shoulders), and in particular for having the largest antlers of any known cervid (a maximum of 13 feet from tip to tip). The name “giant deer” is sometimes preferred; although large numbers of its skeletons have been found in Irish bogs, the animal was not exclusively Irish, and neither was it closely related to either of the living species currently called “elk”.
The latest known remains of the Irish elk have been carbon dated to about 5700 BC[1] (http://www.cbc.ca/story/science/national/2004/10/06/deer041006.html).
The size of the Irish Elk's antlers is remarkable, and some evolutionists have felt that their purpose demands an explanation. One theory was that the Elk's antlers, under constant sexual selection, increased in size because males were using them in combat for access to females; it was also suggested that they eventually became so unwieldy that the Elks could not carry on the normal business of life and so became extinct. However, Stephen Jay Gould's important essay on Megaloceros demonstrated that for deer in general, species with larger body size have antlers that are more than proportionately larger, a consequence of allometry, or differential growth rate of body size and antler size during development. In fact, Irish Elk had antlers of exactly the size one would predict from their body size and no special story of natural selection is required.
The antlers do seem to have played a role in the animal's eventual extinction, however. Recent research has determined that due to the high amounts of calcium and phosphate compounds required to form these massive structures, the Irish Elk males had to deplete these compounds partly from their bones, replenishing them from foodplants when the antlers were grown. Thus, in the growth phase, males were suffering from a condition similar to osteoporosis. When the climate changed at the end of the last Ice Age, the vegetation in the animal's habitat also changed towards species that could not deliver sufficient amounts of the required minerals. Thus, the delicate balance between the animal and its environment was broken—coupled with hunting by humans (facilitated by the weakening of the males' bones during antler growth), this was the probable cause of this animal's extinction.
A significant collection of Irish Elk skeletons can be found at the Natural History branch of the National Museum of Ireland in Dublin.
External links
- Computermade picture from "Walking with Beasts"[2] (http://dsc.discovery.com/convergence/beasts/photo/photo_zoom5.html)
- Factfile from BBC[3] (http://www.bbc.co.uk/nature/wildfacts/factfiles/461.shtml)
- University of Berkleys page "The Case of the Irish Elk"[4] (http://www.ucmp.berkeley.edu/mammal/artio/irishelk.html)
Bibliography
- Stuart, A. J., P. A. Kosintsev, T. F. G. Higham, and A. M. Lister. Pleistocene to holocene extinction dynamics in giant deer and woolly mammoth. Nature 431: 684-689 (October 07, 2004)de:Megaloceros