Woolly rhinoceros

## Coelodonta

C. antiquitatis. Credit: Dinomaniac on DeviantArt.

*Coelodonta*, the woolly rhinoceros (*C. antiquitatis*) and the Tibetan woolly rhinoceros (*C. thibetana*), known as a woolly rhino for short, is an extinct species of rhinoceros that lived in Eurasia during the Pleistocene.

## History

*C. tologojensis* was originally described from Asia, with a skull found in the Kyffhauser hills, near Bed Frankenhausen, Germany assigned (not as holotype). It is believed to have reached Europe by 478,000 and 424,000 years during a cold aridity period. However, a 2022 study suggested that this skull is better assigned to the woolly rhinoceros. *C. thibetana* is one of the most basal species in this genus, known from the western Himalayas during the Middle Pliocene. The holotype (IVPP V15908), a partial skull and incomplete mandible with full dentition, was named by Deng et al. (2011).

## Description

Woolly rhinoceros remains have been found way before scientific description, often misinterpreted as another animal entirely (like stating the horn was a talon of ancient massive birds). Woolly rhinoceroses were about as large as the white rhinoceros; being about 2 meters (6.6 feet) tall at the shoulder, 1800-2700 kilograms (4000-6000 pounds) heavy and about 3-3.8 meters (9.8-12.5 feet) long. Calfs have been found frozen on permafrost, one one-month old calf was calculated to be about 120 centimeters (3.9 feet) long and about 72 centimeters (2.36 feet) tall at the shoulder. The species sported two horns on its head, one large curved one, and a smaller arched one. Both horns were made of keratin, and the large one sat above the nose and pointed backwards, and the shorter horn sat between the eyes. The woolly rhinoceros had a stronger body, shorter legs compared to other rhinoceroses, and had a large raised hump on its shoulders. The large hump contained large muscles to support the weight of the head and fat reserve to fuel the animal in the harsh mammoth steppe.

Frozen individuals indicate that the animals fur coat was a reddish brown, with a thick undercoat underneath long coarse hairs, reaching its thickest on the neck. Shorter hairs lined its limbs, to keep snow from becoming stuck to the animals body. The body rounds off, and is tipped by a 40-50 centimeter (1.48-1.64 feet) tail with a brush of coarse hairs. Female individuals had two nipples on their udders. The woolly rhinoceros was built to maintain heat, had ears up to 24 centimeters (9.4 inches) long (rhinos in hot climate have ears up to 30 centimeters (12 inches) long). Compared to other rhinoceros, woolly rhinos had shorter tails, and had thick hide (ranging from 5-15 millimeters (0.20-0.59 inches)), that was at its thickest points in the chest and shoulders. The skull is from about 70-90 centimeters (28-35 inches) long. The woolly rhinoceros has a skull considerably longer than the skulls of other rhinos. The skull had a deep, down-turned slanted position, most similar to *Stephanorhinus* species, the white rhinoceros and *Elasmotherium*. The animal had an elongated occipital bone, which held large muscles in place. These muscles helped hold the weight of the entire head. The woolly rhino had a large mandible, which was 60 centimeters (24 inches) long and 10 centimeters (3.9 inches) tall. The nasal septum was was ossified, a trait modern rhinos lack. This trait likely evolved because of the combined weight and pressure of the horn, and the animal grazing in thick snow. A feature unique to this particular species is the nasal bones being fused to the premaxillae, a trait lost in older *Coelodonta* species and modern rhinoceroses. Woolly rhinoceroses had thick enamel and an open space inside the tooth. Adults did not have incisors, like other rhinos, but had 3 premolars and 3 molars lining both jaws. The molars are identified by their high crowns, and a thick coat of cementum.

Unlike some rhinoceros species, both sexes had horns. One larger, and another smaller with less of a curve. The front horn could reach up to 1.4 meters (4.6 feet) tall, usually being at least 1 meter in most individuals. The horn was about 15 kilograms (33 pounds) in weight. The front horn faced more far-forward than modern rhinoceroses.

## Paleobiology

The woolly rhinoceros had a similar life history to modern rhinoceros. Studies on woolly rhinoceros udders state that one mother normally cared for one calf, or two at most for two or three years. The calves left their mothers at three years to find a territory, and reached sexual maturity at about 5 years of age. The woolly rhinoceros lived to about 40 years of age, not unlike the modern rhinoceros. Adults had few predators, but infants were sizable game for many predators like hyenas and cave lions. Remains of a woolly rhinoceros show felid bite marks, however the animal survived the attack. Adults used their ornamentation for combat, specifically strength competitions among others of the same species. This function is preserved in cave art. Other uses include ploughing snow to uncover plants and attracting mates. Bulls were likely highly aggressive and competitive, like modern counterparts, particularly during rutting season. Fossil skulls indicate damage caused by other woolly rhinoceroses. Lower jaws and ribs show signs of breakage and healing, which was a likely side effect during rutting season. This increased intraspecies combat was likely an effect of rapid climate change in the last glacial period, causing increased stress among other of the species and competition from other herbivorous megafauna.

## Diet

Woolly rhinos fed mostly on diverse sedges and grasses, vegetation which was abundant in the mammoth steppe. The shape of its teeth and skull were built to help the animal graze. The animal had a wide upper lip, a feature some modern rhinoceros use to help pluck plant matter from the ground. Palynology pollen studies show that woolly rhinoceros also ate wood-based plants, which can include willows, conifers and alders and flowering plants and mosses. Studies on the isotopes in the animals horn states that the woolly rhinoceros also had a seasonal-based diet: mainly grazing in the summer, and it foraged for shrubs and branches in the winter. Analysis on the musculature surrounding the skull finds that the woolly rhinoceros was specifically adapted for grazing. Specifically, the temporalis is enlarged, to give the woolly rhinoceros the ability to tug at large mouthfuls of vegetation rooted in the frozen ground. This theory is further proven by the existence of a large diastema. Wooly rhinoceros were hindgut fermenters, having a single stomach, they ingested cellulose-rich and protein-poor vegetation. As opposed to eating protein-rich fodder, the woolly rhinoceros had to eat considerably more vegetation to obtain large amounts of protein. The woolly rhinoceros lived in the Arctic during the Last Glacial Maximum, and consumed equal amounts of forb, Artemisia and graminoid plants.

## Paleoecology

The woolly rhinoceros lived in lowlands, river valleys and plateaus that had dry and arid climates. Woolly rhinos migrated to higher geographical elevations in certain climate phases, but avoided mountain ranges entirely due to heavy snow fall and steep terrain the animal could not traverse easily. Woolly rhinos lived alongside the woolly mammoth, Irish elk, Saiga, and European bison. This range of animals is known as the *Mammuthus*-*Coelodonta* Faunal Complex. Alongside this vast assortment of herbivores, the woolly rhinoceros also coexisted with *Stephanorhinus* and *Elasmotherium* in it's vast range.

By the end of the Riss Glaciation about 130 thousand years ago, woolly rhinoceroses lived though out northern Eurasia, the Siberian Plain and Siberia, and the Mongolian Plateau. This locations ranged form 72° to 33°. Fossils have been as far north as the New Siberian Islands, proving this species had the largest range of any rhinoceros species known.

Seemingly, the woolly rhinoceros did not cross over the Bering land bridge during the final ice age. The animals eastern-most appearance is the Chukot Peninsula. This is likely because of the low grass density and lack of suitable habitat in the Yukon, competition with other large herbivores on the land bridge and glaciers creating vast boundaries. If some arrived in North America (the destination of said land bridge), it would have been an uncommon occurrence.

### Relationship with Humans

The woolly rhinoceros and humans lived in the same environment, but evidence that they interacted is increasingly rare. Only 11% of known human sites depict the animal, which is strange due to ancient humans love for depicting the animals they lived with. Many remains exist outside of their boundaries, which means it is possible predators like hyenas carried their remains outside of their territories, scattering their bones. Sometimes, bone fragments and teeth are uncovered, which belong to the same individual. Most remains are found where human artifacts and remains are, though it is likely a natural occurrence.

Most evidence of species interaction comes from visible wounds found in the animals skeleton. Some specimens have wounds caused by human weaponry, traces of sharp materials lodged in their skeletons and even spears uncovered nearby the rhino in question. Several human caves have arrangements of woolly rhinoceros bones that are heavily slashed, beaten, and destroyed. This action may have been done to extract bone marrow.

The horns and bones of woolly rhinoceros were used as tools and raw materials. One contraption was made by a beaten-in woolly rhinoceros pelvis, others include spears and special figures. The latter, has been dubbed the Pinhole Cave Man. The figure was carved from woolly rhinoceros ribs.

Many Upper Paleolithic caves feature woolly rhinoceros. Their features are prominently painted, including a back hump, a low-lying head. Two arched lines represent ears and their horns are shown with great curvature. Some cave paintings indicate a shaggy coat, and most have a black band separating their shoulders from their pelvis'. This may indicate a black band was present on the animals coat; an indication of colouration. One painting has two individuals in combat, another has a raised head, and some pierced with spears indicating human predation.

## Notable Specimens

* "Tirekhtyakh specimen": This specimen was discovered in Yakutia in 2020, and is the most intact juvenile woolly rhinoceros carcass. The specimen is hazel-coloured, preserving most of the animals internal organs, fat, hair, bones and teeth. The remains were discovered mid-August by the river Tirekhtyakh in the Abyisky ulus of Siberia. The stomach and intestinal contents preserved, and yet to be examined. The individual was young, likely about 3 or 4, and was separate from it's mother at death, likely caused by drowning. The individual's gender is yet unknown, awaiting radiocarbon tests. It likely lived 20-50 thousand years ago, and probably died in the Summer. The carcass is 80% intact and was discovered by local Alexei Savvin.
* MNVD-G 11.144: A skull fragment from the Seweckenberge fossil assemblage from the left side of a juvenile's skull. It was found in fine-grained sediments. The morphology of the DP3 and DP4 identify it as woolly rhinoceros.

## Gallery

### Skeletons

A cutaway tooth showing the hollow cavity the species was named for.**Credit: ResearchGate.**
### Reconstructions

**Credit: Roman Uchytel.****Credit: Panzareta on DeviantArt.****Credit: Paleop on DeviantArt.****Credit: Eurwentala on DeviantArt.****Credit: DeinonychusEmpire on DeviantArt.****Credit: Gabriel Ugueto.****Credit: Sphenaphinae on DeviantArt.**Woolly rhinoceros and aiga antelope.
**Credit: Benjamin Langlois on Twitter.**Interpretation of human cave art by Julio Lacerda.

## References

* https://en.wikipedia.org/wiki/Woolly\_rhinoceros
* https://en.wikipedia.org/wiki/Coelodonta\_thibetana
* https://en.wikipedia.org/wiki/Coelodonta\_tologoijensis
* https://siberiantimes.com/other/others/news/a-well-preserved-woolly-rhino-with-its-last-meal-still-intact-found-in-the-extreme-north-of-yakutia/
* https://scholarlypublications.universiteitleiden.nl/access/item%3A3256424/view