Recently, the oldest known woolly rhinoceros fossil was discovered from 3.6 million years in the Himalayas on the cold Tibetan Plateau, meaning it existed there during a period of general climate warmth around the earth. It is believed that they migrated from there to northern Asia and Europe when the Ice Age began.
AppearanceThe external appearance of woolly rhinos is known from mummified individuals from Siberia as well as cave paintings. An adult woolly rhinoceros was 3.7 metres (12 feet) in length, and 2 to 3 tons on average, but they could probably grow to 4.3 - 4.4 meters (over 14 feet) at the largest. The woolly rhinoceros could grow up to be 2 meters tall. Two horns on the skull were made of keratin, the anterior horn being 2 feet in length, with a smaller horn between its eyes. It had thick, long fur, small ears, short, thick legs, and a stocky body. Cave paintings suggest a wide dark band between the front and hind legs, but it is not universal and identification of rhinoceros as woolly rhinoceros is uncertain. The woolly rhinoceros used its horns for defensive purposes and to attract mates.
As the last and most derived member of the Pleistocene rhinoceros lineage, the woolly rhinoceros was supremely well adapted to its environment. Stocky limbs and thick woolly pelage made it well suited to the steppe-tundra environment prevalent across the Palearctic ecozone during the Pleistocene glaciations. Its geographical range expanded and contracted with the alternating cold and warm cycles, forcing populations to migrate as glaciers receded. Like the vast majority of rhinoceroses, the body plan of the woolly rhinoceros adhered to the conservative morphology, like the first rhinoceroses seen in the late Eocene. A close relative, the Elasmotherium had a more southern range.
DietControversy has long surrounded the precise dietary preference of Coelodonta as past investigations have found both grazing and browsing modes of life to be plausible. The palaeodiet of the woolly rhinoceros has been reconstructed using several lines of evidence. Climatic reconstructions indicate the preferred environment to have been cold and arid steppe-tundra, with large herbivores forming an important part of the feedback cycle. Pollen analysis shows a prevalence of grasses and sedges within a more complicated vegetation mosaic.
A strain vector biomechanical investigation of the skull, mandible and teeth of a well-preserved last cold stage individual recovered from Whitemoor Haye, Staffordshire, revealed musculature and dental characteristics that support a grazing feeding preference. In particular, the enlargement of the temporalis and neck muscles is consistent with that required to resist the large tugging forces generated when taking large mouthfuls of fodder from the ground. The presence of a large diastema supports this theory.
Comparisons with extant perissodactyls confirm that Coelodonta was a hindgut fermentor with a single stomach, and as such would have grazed upon cellulose-rich, protein-poor fodder. This method of digestion would have required a large throughput of food and thus links the large mouthful size to the low nutritive content of the chosen grasses and sedges.
FossilsWhen Woolly Rhinoceros horns were found in Russia during the 19th century, many believed that the strange-looking objects were the claws of giant birds. Frozen carcasses found since in Siberia completed the picture. The horns are worn down on the under surface which suggests they were swept back and forth sideways on the ground. This may have been to help clear snow off the grass, or as part of a ritual display, as in some modern rhinos. The woolly rhino's closest living relative is the Sumatran rhino. It had a pair of two big horns.
Coelodonta, better known as the Woolly Rhino, is one of the few Ice Age megafauna mammals to be memorialized in cave paintings (another example is the Auroch, the precursor to modern cattle). This is appropriate, since it was almost certainly hunting by the early humans of Eurasia that drove Coelodonta into extinction. (Clearly the Woolly Rhino was coveted not only for its meat, but for its thick fur pelt, which could clothe an entire village!)
Aside from its mammoth-like fur coat, the Woolly Rhino was very similar to modern rhinoceroses, its immediate descendants—that is, if you overlook this herbivore's odd, paired horn structure, a big, upward-curving one on the tip of its snout and a smaller pair set further up, nearer its eyes. It's believed that the Woolly Rhino used its horns not only as a sexual display (i.e., males with bigger horns had the opportunity to mate with more females), but also to clear snow away from the Siberian tundra and nibble on the underlying grass.Coelodonta are fossilized rhinoceroses which adjusted to life in the dry and cool conditions of open landscapes of Eurasia. They existed from the late Pliocene until the early Holocene and were typical representatives of Pleistocene megafauna.
Coelodonta was a large, relatively short-legged animal with high withers and an elongated skull that carried two horns.
Its massive body reached 3.2-4.3 meters in length, and 1.4–2 meters in height. The characteristic feature of these animals was their well-developed woolly coat that protected them from low temperatures and cold winds. The low position of their head and their square lips allowed picking up their main forage – steppe and tundra vegetation. The increasingly severe continental climate affected the appearance and habits of these animals making northern rhinoceroses able to survive even in the tundra. Their morphology underwent changes; the position of their head became different – it moved lower to the ground, their skulls elongated even further and narrowed, their eye-sockets moved closer towards the occiput, and their teeth evolved to adjust to masticating harsh steppe vegetation. For protection from the intensifying cold, they developed dense woolly coats. At the end of Pleistocene and at the beginning of the Holocene, Coelodonta unfortunately disappeared. Presumably, it happened mainly due to the climate change which accompanied the end of the last ice age: due to global warming and increased humidity, the area suitable for woolly rhinoceroses dramatically decreased.
The Tibetan woolly rhinoceros (Coelodonta thibetana) is an extinct species of woolly rhinoceros native to western Himalayas that lived during the middle Pliocene epoch. C. thibetana is known from the holotype IVPP V15908, a partially complete skull including incomplete lower jaw preserved with full dentition. It was first named by Tao Deng, Xiaoming Wang, Mikael Fortelius, Qiang Li, Yang Wang, Zhijie J. Tseng, Gary T. Takeuchi, Joel E. Saylor, Laura K. Säilä and Guangpu Xie in 2011. It is the oldest Woolly Rhino ever discovered and the fossil skull was found in 2011.This newly rhino rhino is 3.6 million years old (middle Pliocene), much older and more primitive than its Ice Age (Pleistocene) descendants in the mammoth steppes across much of Europe and Asia. The extinct animal had developed special adaptations for sweeping snow using its flattened horn to reveal vegetation, a useful behavior for survival in the harsh Tibetan climate. These rhinos lived at a time when global climate was much warmer and the northern continents were free of the massive ice sheets seen in the Ice Age later.
The rhino accustomed itself to cold conditions in high elevations and became pre-adapted for the future Ice Age climate. When the Ice Age eventually arrived around 2.6 million years ago, the new paper posits, the cold-loving rhinos simply descended from the high mountains and began to expand throughout northern Asia and Europe.
In addition to the new woolly rhino, the paleontologist team also uncovered extinct species of three-toed horse (Hipparion), Tibetan bharal (Pseudois, also known as blue sheep), chiru (Pantholops, also known as Tibetan antelope), snow leopard (Uncia), badger (Meles), as well as 23 other kinds of mammals.
The team's new fossil assemblage from Tibet offers new insights into the origin of the cold-adapted Pleistocene megafauna, which has usually been sought either in the arctic tundra or in the cold steppes elsewhere. This new evidence offers an alternative scenario: the harsh winters of the rising Tibetan Plateau may have provided the initial step towards cold-adaptation for several subsequently successful members of the late Pleistocene mammoth fauna in Europe, Asia, and to a lesser extent, North America. The Tibetan Plateau may have been another cradle of the Ice Age giants.
"This discovery clarifies the origin of the woolly rhinoceros — and perhaps much of the now extinct, cold-adapted, Pleistocene Eurasian megafauna — as the high-altitude environments of the Zanda Basin of the primordial Pliocene Himalayas," said H. Richard Lane of the National Science Foundation (NSF)'s Division of Earth Sciences.