Camelus knoblochi

Camelus knoblochi is an extinct species of camel from the Pleistocene. One of the largest known camel species, its range spanned from Eastern Europe to Northern China.

History of discovery
The earliest remains of the species were collected from the Volga region of Russia. The species was first recognised as distinct species in an 1880 paper by I. S. Poliakov, but this was never published. The species was properly named in 1901 by A. Nehring, based on a fossil skull and lower jaws collected at the Luchka locality in the lower Volga, with the species name being after Alexander Knobloch, a factory owner in the nearby town of Sarepta interested in fossils who sent the skull in 1880 to the Zoological museum of St. Petersburg.

Evolution
Sequenced genomes of C. knoblochi suggests that while the species is distinct from the living Camelus ferus (wild Bactrian camel) at the nuclear genomic level, its mitochondrial genome diveristy is nested within that of the wild Bactrian camel, likely as a result of interbreeding with that species. While clearly a genetically distinct species in its own right which is more closely related to both the living wild Bactrian camel and the domestric Bactrian camel (Camelus bactrianus) than to the dromedary, it forms an effective polytomy with the two living Bactrian camel species likely due to interbreeding between the species as well as the three species diverging from each other around the same time. Genome analysis indicates that all 3 species had been genetically distinct from each other for at least 400,000 years. Cladogram after Yuan et al. 2024:

The earliest fossils of C. knoblochi date to the Middle Pleistocene.

Description
Camelus knoblochi is one of the largest known species of genus Camelus, being considerably larger than the 3 living camel species. C. knoblochi has been estimated to reach around 3 m tall and over 1000 kg in weight. Its bones are more physically massive than those of living camels. The facial part of the skull is around 60% of the total length, somewhat elongate relative to other members of Camelus. The premaxillary bones are unfused. The metatarsals are slightly more elongate than the metacarpals on average.

Distribution and ecology
Remains of Camelus knoblochi span from Ukraine in the west, southwards into the Caucasus and Central Asia, and across the Urals into Mongolia and into Northeast China. During the Late Pleistocene, its distribution was restricted from the Urals eastwards. The habitat of the species was primarily steppe, and to a lesser degree, forest steppe, rather than the desert environments inhabited by living Bactrian camel species. During the Late Pleistocene in Mongolia and northern China, the species coexisted alongside other megafauna like the woolly rhinoceros, the giant deer Sinomegaceros ordosianus, Przewalski's horse, Asiatic wild asses, and argali.

Isotopic analysis suggests that the species was a browser on C3 vegetation.

Relationship with humans
At Tsagaan Agui Cave in Mongolia, a metacarpal of the species, dating to around 59-44,000 years Before Present, bears fracture marks as a result of human butchery like to access the marrow cavity, with bite marks showing that it was subsequently gnawed on by cave hyaenas. Pleistocene cave art from Mongolia may also depict the species.

Extinction
The latest remains of the species are from the Gobi Desert of Mongolia, where the species became extinct around the Last Glacial Maximum (around 26-19,500 years ago). Genetic analysis suggests that the species had already been in population decline for tens of thousands of years prior. The species likely went extinct as a result of unfavourable environmental change, including the aridification of the Gobi Desert around this time.