The Irish Elk (Megaloceros giganteus) is an extinct deer that lived in Europe during the Pliocene and Pleistocene epochs. It is famous for its formidable size, and in particular for having the largest antlers of any known deer. 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 creature stood about two meters at the shoulder, and is thought to have died out around 9000 B.C.E.[1] (http://dsc.discovery.com/convergence/beasts/photo/photo_zoom5.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 natural 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 a 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.