Rucervus
Rucervus is a genus of deer from India, Nepal, Indochina, and the Chinese island of Hainan. The only extant representatives, the barasingha ("R. duvaucelii)" and Eld's deer ("R. eldii"), are threatened by habitat loss and hunting, and another species ("R. schomburgki)" became extinct in 1938. The species of the genus "Rucervus" are characterized by a specific antler structure: its basal ramification is often supplemented with an additional small prong, the middle tine is never present, while the crown tines are inserted on the posterior side of the beam and may be bifurcated or fused into a small palmation . Species. Extinct species. According to the old tradition of zoological taxonomy, swamp deer originally were regarded as members of the genus "Cervus. Rucervus" was originally proposed by Hodgson as a subgenus of the genus "Cervus." The original definition of "Rucervus" was mostly based on antler shape believed to be intermediate between that of "'elaphus"' and '"hippelaphus"'. Hodgson reported that upper canines are present only in males of barasingha, but the additional craniological material shows that upper canines are present in both sexes. Eld's deer was regarded as another species of the genus "Rucervus", however, the recent genetic evidences suggest  that the Eld's deer should be moved back to "Cervus", or placed in its own genus, "Panolia". It has recently been place back into "Rucervus" by the American Society of Mammalogists. "Rucervus" is an ancient cervid lineage that--together with the genus "Axis"--represents the oldest evolutionary radiation of the subfamily Cervinae (plesiometacarpal deer). Paleontological record. The fossil species of "Rucervus" of Europe were included in the genus "Arvernoceros" Heintz, 1971 (the type species: "Cervus ardei" Croizet & Jobert, 1828) or in the genus "Eucladoceros", as in the case of "R. giulii". Today, "Arvernoceros" is regarded as a subgenus of "Rucervus . The European fossil forms of Rucervus" are distinguished from the South Asian species by more compact crown part of the antler and by the frequent development of a small distal palmation as for instance in "R. ardei" and "R. radulescui". South Asian fossil forms of "Rucervus" are represented by large-sized "R. simplicidens" and "R. colberti". The late Early Pleistocene of Greece has yielded the remains of a giant species "R. gigans" that rivaled in size Irish elk "Megaloceros giganteus", The giant "Rucervus" from Greece is distinguished by unusually for such a large animal long limbs and apparently is closely  related to "R. simplicidens" and "R. colberti" from the Sivaliks. The Southwest-Europe endemic Mid to early Late Pleistocene genus "Haploidoceros" is regarded as closely allied.