Irish elk
The Irish elk stood about tall at the shoulders and carried the largest antlers of any known deer, a maximum of from tip to tip and in weight. For body size, at about and up to or more, the Irish elk was the heaviest known cervine ("Old World deer"); and tied with the extant Alaska moose ("Alces alces gigas") as the third largest known deer, after the extinct "Cervalces latifrons" and "Cervalces scotti". Nonetheless, compared to "Alces", Irish elk appear to have had a more robust skeleton, with older and more mature "Alces" skeletons bearing some resemblance to those of prime Irish elk, and younger Irish elk resembling prime "Alces". Likely due to different social structures, the Irish elk exhibits more marked sexual dimorphism than "Alces", with Irish elk bucks being notably larger than does. In total, Irish elk bucks may have ranged from , with an average of , and does may have been relatively large, about 80% of buck size, or on average. The distinguishing characters of "M. giganteus" include concave frontals, proportionally long braincase, proportionally short front section of the skull (orbitofrontal region), alongside the absence of upper canines and the molarisation of the lower fourth premolar (P4). The skull and mandible of the Irish elk exhibit substantial thickening (pachyostosis), with the early and complete obliteration of cranial sutures.