Narrow-nosed rhinoceros

The narrow-nosed rhinoceros (Stephanorhinus hemitoechus), also known as the steppe rhinoceros is an extinct species of rhinoceros belonging to the genus Stephanorhinus that lived in western Eurasia, including Europe, as well as North Africa during the Pleistocene. It first appeared in Europe around 500,000 years ago during the Middle Pleistocene and survived there until at least 34,000 years Before Present.

Taxonomy
The species was originally described by Hugh Falconer in 1859 based on remains found in cave deposits in Glamorganshire, south Wales in Great Britain, dating to the Eemian interglacial (130-115,000 years ago).

Description
The narrow-nosed rhinoceros was a large animal, reaching a body mass of approximately 1500 kg, making it around the same size/slightly larger than S. hundsheimensis, but smaller than S. kirchbergensis. The size of the species was somewhat variable depending on local conditions. The skull is low slung, with the cranium being downwardly directed. The teeth are relatively high crowned (hypsodont) compared to other Stephanorhinus species, with the third molars being relatively enlarged. Compared to the earlier species S. jeanvireti, S. etruscus, and S. hundsheimensis the limb joints are relatively shallow, and the limb bones relatively broad and short.

Distribution
In comparison to the widespread Merck's rhinoceros (Stephanorhinus kirchbergensis), the narrow-nosed rhinoceros had a less geographically extensive distribution, including much of Europe, as well as West Asia and North Africa. In Europe the species is known from abundant remains in the Iberian Peninsula in the west (where S. kirchbergensis appears to have been rare or absent), eastwards to Italy, Bulgaria and Greece.  Its range extended northwards into northern France, Britain (as far north as North Yorkshire ), Germany and Slovakia during warm interglacial periods.

In North Africa, where the species was previously known as Rhinoceros subinermis , remains are known from Cyrenacia in northeast Libya and the Atlas Mountains in Morocco and northern Algeria. In West Asia, the range of the species extends from the Levant (including Israel, Jordan and Syria ) in the west, as well as western Iran, and Azerbaijan in the east, where some remains were previously referred to as the species ''Rhinoceros binagadensis. ''

Ecology
The morphology of the skull suggests that the species was adapted towards a grazing diet. Tooth wear analysis suggests that the narrow-nosed rhinoceros had a diet tending towards grazing or mixed feeding, and clearly distinct from the more browsing focused diet inferred for S. kirchbergensis on average. Although the species has been referred to as the "steppe rhinoceros" and presumed to have had a preference for open habitats, the species was ecologically plastic, and occurred in both open grasslands and forested environments.

The narrow-nosed rhinoceros lived alongside other megafauna species, including both animals present today, like red deer, wolves and brown bears, and those that are extinct, like wild horse, European wild ass, aurochs, Irish elk, steppe lions and straight-tusked elephants.

Human exploitation
Finds at a number of sites suggest that the narrow-nosed rhinoceros was exploited for food by archaic humans. Specimens of S. hemitoechus from the Middle Pleistocene (Marine Isotope Stage 12, 478,000-424,000 years ago) Arago Cave (Caune de l'Arago) site in Southern France shows extensive evidence of butchery (presumably by Tautavel Man, which is found at the same site). The ratios of skeletal elements implies that only the parts of the body with the most meat were carried to the site. The profile of ages of rhino bones in the cave resembles natural mortality curves, suggesting that there was not selective hunting, and the fact that marks of other carnivores are rare implies that the carcasses were acquired by hunting or active scavenging. At the Shishan Marsh site in the Azraq Oasis in northeast Jordan, dating to around 250,000 years ago, stone tools at the site have been found to have protein residue from the butchery of rhinoceroses. As S. hemitoechus is the only rhinoceros species known from the site, it is probable that it was the species butchered.

At the late Middle Pleistocene Gran Dolina site in Spain, a handful of ''S. cf. hemitoechus'' bones display cut marks. At Biache-Saint-Vaast in northeast France, dating to MIS 7, around 240,000 years ago, remains of at least 33 individuals of S. hemitoechus were found in association with human artifacts, with a significant proportion displaying cut marks. The mortality profile, which is heavily skewed towards juveniles, with no old adults, may suggest selective hunting of juveniles by Neanderthals. At the collapsed cave of Payre in southeast France, dating to the late Middle Pleistocene, numerous remains of S. hemitoechus along with S. kirchbergensis have been found, which display marks indicative of butchery and are suggested to have been accumulated at the site by Neanderthals. The abundance of teeth found at the site (though other skull material is largely absent) suggests that the Neanderthals may have been using them as tools. Mortality profiles found that young and old individuals were the most abundant at the site.

A skull from Cueva Des-Cubierta in central Spain, dating to the early-mid Late Pleistocene (MIS 4-early MIS 3, ~71-43,000 years ago), exhibits fracturing and cut marks consistent with butchery by Neanderthals. The missing pieces of the skull were not found in the cave, suggesting that it had been butchered off-site. It has been proposed that the skull was kept as a hunting trophy along with the skulls of aurochs and bison. Several other sites in Spain demonstrate the exploitation of S. hemitoechus by Neanderthals during the early-mid Late Pleistocene, including Navalmaíllo Rock Shelter and Abric Romani.

Evolution and extinction
The earliest remains of the species in Europe date to the early-mid Middle Pleistocene, around 500,000 years ago. It is suggested to have evolved outside of Western Europe before later migrating into the region. The species may have evolved from the earlier Stephanorhinus etruscus. In North Africa, remains of the narrow-nosed rhinoceros are known dating between 109-53,000 years ago. In Europe, the narrow-nosed rhinoceros survived latest in the southern parts of its range. The last records in Italy date to around 41,000 years ago, while remains dating to 40,000 years ago are knowns from Bacho Kiro cave in Bulgaria. In the Iberian Peninsula, the latest records of the species date to 34,000 years ago. In the Levant, the species may have survived as recently as 15,500 years ago based on remains found in Hayonim Cave, Israel. Its extinction is suggested to be due at least in part due to climatic change causing habitat fragmentation resulting in population fragmentation, with small populations more likely to become extinct as a result of stochastic processes.