Irish elk

The Irish elk (Megaloceros giganteus), also called the giant deer or Irish deer, is an extinct species of deer in the genus Megaloceros and is one of the largest deer that ever lived. Its range extended across northern Eurasia during the Pleistocene, from Ireland (where it is known from abundant remains found in bogs) to Lake Baikal in Siberia. The most recent remains of the species have been radiocarbon dated to about 7,700 years ago in western Russia. Its antlers, which can span over across, are the largest known of any deer. It is not closely related to either living species called the elk, with it being widely agreed that its closest living relatives are fallow deer (Dama).

Taxonomy

Research history

thumb|left|Skeletal reconstruction from 1856

The first scientific descriptions of the animal's remains were made by Irish physician Thomas Molyneux in 1695, who identified large antlers from Dardistown—which were apparently commonly unearthed in Ireland—as belonging to the elk (known as the moose in North America), concluding that it was once abundant on the island. It was first formally named as Alce gigantea by Johann Friedrich Blumenbach in his Handbuch der Naturgeschichte in 1799, with Alce being a variant of Alces, the Latin name for the elk. The original Blumenbach's description of Alce gigantea provides rather scant information about the species, specifying only that this particular kind of "fossil elk" comes from Ireland and is characterized by immense body size. According to Blumenbach, that was figured and described for the first time in Louthiana of Thomas Wright. The holotype of Megaloceros giganteus (Blumenbach, 1799) is a well-preserved male skull with exceptionally large antlers found in Dunleer environs (County Louth, Ireland). The type and only species named in the description being Megaloceros antiquorum, based on Irish remains now considered to belong to M. giganteus, making the former a junior synonym. The original description was considered by Adrian Lister in 1987 to be inadequate for a taxonomic definition. In 1828 Brookes published an expanded list in the form of a catalogue for an upcoming auction, which included the Latin phrase "Cornibus deciduis palmatis" (meaning "deciduous palmate antlers") as a description of the remains. The 1828 publication was approved by International Commission on Zoological Nomenclature (ICZN) in 1977 as an available publication for the basis of zoological nomenclature. George Gaylord Simpson in 1945 revived the original Megaloceros name, which became progressively more widely used, until a taxonomic decision in 1989 by the ICZN confirmed the priority of Megaloceros over Megaceros, and Megaloceros to be the correct spelling.

Before the 20th century, the Irish elk, having evolved from smaller ancestors with smaller antlers, was taken as a prime example of orthogenesis (directed evolution), an evolutionary mechanism opposed to Darwinian evolution in which the successive species within the lineage become increasingly modified in a single undeviating direction, evolution proceeding in a straight line void of natural selection. Orthogenesis was claimed to have caused an evolutionary trajectory towards antlers that became larger and larger, eventually causing the species' extinction because the antlers grew to sizes which inhibited proper feeding habits and caused the animal to become trapped in tree branches. The currently favoured view is that sexual selection was the driving force behind the large antlers rather than orthogenesis or natural selection. The taxonomy of giant deer lacks consensus, with genus names used for species varying substantially between authors. however this species has been subsequently suggested to belong to Arvernoceros Other species often considered to belong to Megaloceros include the reindeer sized M. savini, which is known from early Middle Pleistocene (~700,000–450,000 years ago) localities in England, France, Spain and Germany, and the more recently described species M. novocarthaginiensis, which is known from late Early Pleistocene (0.9–0.8 Ma) localities in Spain, and the small M. matritensis endemic to the Iberian peninsula during the late Middle Pleistocene (~400,000 to 250,000 years ago), which overlaps chronologically with the earliest M. giganteus records. Jan van der Made proposed M. novocarthaginiensis, M. savini and M. matritensis to be sequential chronospecies, due to shared morphological characteristics not found in M. giganteus and gradual transition of morphological characters through time. The earliest possible records of M. giganteus comes from Homersfield, England thought to be about 450,000 years ago—though the dating is uncertain. The oldest securely dated Middle Pleistocene records are those from Hoxne, England, which have been dated to Marine Isotope Stage 11 (424,000 to 374,000 years ago),

Some authors have proposed that Late Pleistocene M. giganteus should be divided into several subspecies including M. giganteus ruffii and M. giganteus giganteus, based primarily on differences in antler morphology. However, another study from the same year in the journal Nature utilising both fragmentary mitochondrial DNA and morphological data found that the Irish elk was indeed most closely related to Dama.

Description

thumb|[[Life restoration]]

thumb|Skeleton of Irish elk exhibited in [[Kelvingrove Art Gallery and Museum in Glasgow]]

The Irish elk stood about tall at the shoulders, the largest of any known deer, with the broadest antlers, such as those on holotype Barmeath Castle skull, reaching from tip to tip, The antlers are considerably larger than those of living moose, being on average over twice the volume of moose antlers. the Irish elk was the heaviest known cervine ("Old World deer"); 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.|alt=]]

In 1998, Canadian biologist Valerius Geist hypothesised that the Irish elk was cursorial (adapted for running and stamina). He noted that the Irish elk physically resembled reindeer. The body proportions of the Irish elk are similar to those of the cursorial addax, oryx, and saiga antelope. These include the relatively short legs, the long front legs nearly as long as the hind legs, and a robust cylindrical body. Cursorial saiga, gnus, and reindeer have a top speed of over , and can maintain high speeds for up to 15 minutes. similar sizes to the moose. A similar change in a typical Irish elk population with prime stags having antlers would result in antler weights of or less in worsening climatic conditions. This is within the range of present-day wapiti/red deer (Cervus spp.) antler weights. They may have also been used for display, to attract females and assert dominance against rival males. A finite element analysis of the antlers suggested that during fighting, the antlers were likely to interlock around the middle tine, the high stress when interlocking on the distal tine suggests that the fighting was likely more constrained and predictable than among extant deer, likely involving twisting motions, as is known in extant deer with palmated antlers.

In deer, gestation time generally increases with body size. A doe may have had a gestation period of about 274 days. Based on this and patterns seen in modern deer, last year's antlers in Irish elk bucks were potentially shed in early March, peak antler growth in early June, completion by mid-July, shedding velvet (a layer of blood vessels on the antlers in-use while growing them) by late July, and the height of rut falling on the second week of August. Geist, believing the Irish elk to have been a cursorial animal, concluded that a doe would have to have produced nutrient-rich milk so that her calf would have enough energy and stamina to keep up with the herd.

Diet and life history

thumb|Skull in front view

The mesodont (meaning neither high (hypsodont) or low (brachydont) crowned) condition of the teeth suggests that the species was a mixed feeder, being able to both browse and graze. Pollen remains from teeth found in the North Sea around 43,000 years old were found to be dominated by Artemisia and other Asteraceae, with minor Plantago, Helianthemum, Plumbaginaceae and willow (Salix). Another earlier specimen from the Netherlands (dating to the Eemian interglacial or early in the Last Glacial Period) was found to have pollen of Apiaceae, including cow parsley (Anthriscus sylvestris), cow parsnip/hogweed (Heracleum), water pennywort (Hydrocotyle), Asteraeceae, Filipendula, Symphytum and grass embedded with its teeth. Bioapatite δ13C and δ18O analysis of the terminal Pleistocene Irish population suggests a grass and forb based diet, supplemented by browsing during stressed periods. Dental wear patterns of specimens from the late Middle and Late Pleistocene of Britain suggest a diet tending towards mixed feeding and grazing, but with a wide range including leaf browsing. Paired dental mesowear and microwear of Irish elk teeth from the Harz Mountains and southern Germany reveal very high degrees of dietary variation, ranging from folivorous browsing to grass-dominated mixed feeding. This pattern likely reflects seasonal variation, as the microwear patterns which reflect the last days to weeks of an animal's diet indicated browsing while the longer lasting mesowear signal evidenced mixed feeding, and highlights the Irish elk's extreme dietary flexibility. Irish elk microwear values in the Carpathian Basin indicate mixed feeding diets, but mesowear values of these specimens, reflecting a longer term dietary signal, show that an individual Irish elk could occupy any dietary category from browser to grazer, highlighting the species' adaptability. Comparisons of bone collagen δ15N between Irish elk and red deer at the Middle Pleistocene site of Schöningen in Germany suggest that grasses were a more important component of the former's diet relative to the latter. δ13C measurements of Irish elk from Abri du Maras may also suggest that they seasonally fed on lichens and mosses, as reindeer do, although it is unclear if their rumen microbiology was adapted for lichen consumption like that of reindeer.

Examination of histological sections of their long bones suggests that the species has relatively rapid growth rates, reaching skeletal maturity by around 6 years of age. Analysis of the cementum layers of their teeth suggests that Irish elk reached a maximum lifespan of at least 19 years, comparable to moose.

Based on the dietary requirements of red deer, a lean Irish elk stag would have needed to consume of fresh forage daily. Assuming antler growth occurred over a span of 120 days, a stag would have required 1,372 g (3 lb) of protein daily, as well as access to nutrient- and mineral-dense forage starting about a month before antlers began sprouting and continuing until they had fully grown. Such forage is not very common, and stags perhaps sought after aquatic plants in lakes. After antler growing, stags could probably satisfy their nutritional requirements in productive sedge lands bordered by willow and birch forests. and De Nadale Cave and Riparo del Broion in northern Italy, dating to 71–69,000 and 50–44,000 years ago, respectively. Other sites probably resulting from exploitation of Irish elk by Neanderthals include Abri du Maras in southeast France, dating to 55–40,000 years ago. A mandible from Ofatinţi, Moldova dating to either the Eemian or the early Late Pleistocene, has been noted for having "tool-made notches on its lateral side".

A handful of Irish elk depictions are known from the art of the Upper Paleolithic in Europe. However, these are much less abundant than the common red deer and reindeer depictions. Only a handful of examples of modern human interaction are known. A terminal Pleistocene (13,710-13,215 cal BP) skull from Lüdersdorf, Germany is noted to have had the antler and facial part of the skull deliberately removed. A calcaneum from an associated lower hind limb from the early Holocene site of Sosnovy Tushamsky in Siberia is noted to have "two short and deep traces of cutting blows", which are interpreted as "clear evidence of butchery".

Extinction

Outside of the Irish Late Pleistocene, remains of Irish elk are uncommon, suggesting that they were usually rare in the areas where they did occur. However, antler size decreased through the Late Pleistocene and into the Holocene, and so may not have been the primary cause of extinction. Such resource constriction may have cut female fertility rates in half.

By the early Holocene, the range of the species had been dramatically reduced, with the youngest records in the eastern part of its range near Lake Baikal dating to around 10,700–10,400 years Before Present (BP), surviving latest in central part of its range within European Russia and Western Siberia. It is suggested that extinction was contributed to by further climatic changes transforming preferred open habitat into uninhabitable dense forest. The final dates of Irish elk in western Russia roughly coincide with the earliest, scattered presence of Neolithic people in the region. The youngest dates in this region from Kamyshlov in Western Siberia and Maloarkhangelsk, Oryol Oblast In European Russia date to around 7,700-7,600 years ago, and it is suggested that it likely became extinct shortly after this time. Lister and Stewart concluded in a study of the extinction of the Irish elk that "it seems clear that environmental factors, cumulatively over thousands of years, reduced giant deer populations to a highly vulnerable state. In this situation, even relatively low-level hunting by small human populations could have contributed to its extinction." Indeed Leeds Philosophical and Literary Society bought a full skeleton in 1847, from Glennon's in Dublin, for £38. This specimen, discovered at Lough Gur near Limerick, is still on display at Leeds City Museum.

In the Coat of arms of Northern Ireland issued in 1924 (with supporters added the next year) an Irish elk is the sinister supporter.

The 2022 album by Irish band Fontaines D.C. Skinty Fia (translating directly to "The Damnation of the Deer" features the Elk on the front cover, and alludes to it throughout the album.

Taxonomy

Research history

Description

Diet and life history

Extinction

See also

References

Further reading

External links