Sinomegaceros

''Sinomegaceros'' is an extinct genus of deer known from the Late Pliocene/Early Pleistocene to Late Pleistocene of Central and East Asia. It is considered to be part of the group of "giant deer" (often referred to collectively as members of the tribe Megacerini), with a close relationship to ''Megaloceros''. Many members of the genus are noted for their distinctive palmate antler brow tines.

Taxonomy

The first species of the genus ''S. ordosianus'' and ''S. pachyosteus'' were named by pioneering Chinese paleontologist C. C. Young as species of ''Cervus'' in 1932 for material from Zhoukoudian. In a review of the paper the subsequent year Dietrich created the name ''Sinomegaceros'' as a subgenus of ''Cervus'' to house the species, with ''S. pachyosteus'' as the type species. Due to the fact that the name was not published in a formal research paper, it was not widely used for several decades after publication. The species ''S. yabei'' was named in 1938. In the following decades various researchers considered it a subgenus of ''Megaloceros'', or a distinct genus. Several named species are likely to be junior synonyms.

Named species include:

* ''Sinomegaceros tadzhikistanis,'' known from the Late Pliocene-Early Pleistocene of Tajikistan
* ''Sinomegaceros konwanlinensis'', from Gongwaling in Northern China, dating to the Early Pleistocene, around 1.6 million years ago.
* ''Sinomegaceros fabellatus,'' known from the late Early Pleistocene-Early Middle Pleistocene of China
* ''Sinomegaceros'' ''sangwonensis'' known from the mid-Middle Pleistocene of China
* ''Sinomegaceros luochuanensis'' known from the late Middle Pleistocene of China
* ''Sinomegaceros'' ''baotouensis'' known from the Late Pleistocene of China
* ''Sinomegaceros'' ''pachyosteus'' known from the early Middle Pleistocene to the late Middle Pleistocene or Late Pleistocene of China
* ''Sinomegaceros ordosianus,'' known from the late Middle Pleistocene-Late Pleistocene of China and small adjacent areas of Russian Siberia
* ''Sinomegaceros yabei'' late Middle Pleistocene-Late Pleistocene of Japan
Indeterminate remains of ''Sinomegaceros'' are also known from the Late Pleistocene of the Korean Peninsula.

''Sinomegaceros'' has often been considered closely related to other genera "giant deer", like ''Praemegaceros'' and ''Megaloceros'', as part of the tribe Megacerini.'''' Mitochondrial genomes from Late Pleistocene Chinese and Siberian ''Sinomegaceros'' (including ''S. ordosianus'' and ''S. pachyosteus'') indicate that the mitochondrial diversity of the Irish elk (''Megaloceros giganteus'', also known as the giant deer) is nested within the diversity of ''Sinomegaceros,'' suggesting that the two lineages interbred after their initial split. This interbreeding may have occurred in the contact region between the two groups in Siberia. Relationships of ''Sinomegaceros'' mitochondrial genomes after Xiao, et al. 2023

Description

Species of ''Sinomegaceros'' were large deer, with estimated body masses for Chinese Pleistocene species ranging from in ''S.'' ''pachyosteus'' to in ''S. konwanlinensis,'' with ''S. ordosianus'' estimated at . Remains attributed to the genus in Central Asia are even larger, with the body mass of ''S. tadzhikistanis'' being estimated at , while an indeterminate species from the Pleistocene locality of Lakhuti 2 in Tajikistan was estimated , making it one of the largest deer known.^{supplemental material} The antlers have palmate brow tines, with the palmation generally orientated transversely and vertically.Citation: Mei HJ, Zhang B, Lei HR, et al
Antler fossil of ''Sinomegaceros ordosianus'' from Nanbaishan site of Late Pleistocene age in Yüxian, Hebei Province[J
">">Antler fossil of ''Sinomegaceros ordosianus'' from Nanbaishan site of Late Pleistocene age in Yüxian, Hebei Province[J
''Acta Anthropologica Sinica'', 2023, 42(2): 225-237 (In Chinese with English abstract) The mandibles of ''Sinomegaceros'', like those of ''Megaloceros giganteus'', are robust and display pachyostosis with the robustness being the most extreme in ''S. pachyosteus''.

Ecology

''S. yabei'' and ''S. pachyosteus'' are suggested to have been grazers.

Evolution

One of the oldest species in the genus is ''Sinomegaceros tadzhikistanis,'' known from the Late Pliocene-Early Pleistocene of Tajikistan. The oldest species of the genus in China is ''Sinomegaceros konwanlinensis'', from Gongwaling in Northern China, dating to the Early Pleistocene, around 1.6 million years ago. ''S. fabellatus'' is known from fossils spanning the latest Early Pleistocene to early Middle Pleistocene. ''S''. ''sangwonensis'' is known from fossils spanning the mid-Middle Pleistocene. The oldest fossils of ''S. pachyosteus'' date to around 700,000 years ago, during the early Middle Pleistocene. While some authors suggest youngest fossils of the species date to the late Middle Pleistocene, other sources have suggested that the species persisted into the Late Pleistocene, with reported radiocarbon dates as recent as 35,000 years ago. The species ''S. yabei'' and ''S. ordosianus'' first appeared during the late Middle Pleistocene. It has been suggested that both ''S. pachyosteus'' and ''S. yabei'' ultimately derive from ''S. konwanlinensis.'' While often stated to have become extinct around 12,000 years ago, a lack of high-quality radiocarbon dates makes the time of extinction uncertain for ''S. yabei,'' with the only certain radiocarbon dates dating to around 40,000 years ago. Radiocarbon dates for ''S. ordosianus'' in Northeastern China extend as recently as the Last Glacial Maximum, around 22,000 years ago.

Relationship with humans

Remains of ''S. yabei'' at Lake Nojiri in Nagano Prefecture of Honshu, Japan, dating to approximately 37,900 to 42,600 years Before Present have been found associated with spear-shaped wood pieces and large pebbles, with the long bones fractured, with their fragments bearing percussive marks, suggesting that these deer (alongside elephants belonging to the species ''Palaeoloxodon naumanni'') were butchered by humans at the site, with the long bones likely cracked to extract bone marrow. ''S. ordosianus'' is suggested to have likely been hunted by archaic humans, based on the finds of its remains in Chinese Paleolithic archaeological sites.

References

External links

{{Taxonbar, from=Q57081337

Cervinae
Pleistocene mammals of Asia
Prehistoric Artiodactyla genera