''Rhinotitan'' (nose giant) is an
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
brontothere
Brontotheriidae is a family of extinct mammals belonging to the order Perissodactyla, the order that includes horses, rhinoceroses, and tapirs. Superficially, they looked rather like rhinos, although they were actually more closely related to ...
from the
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...
of
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
, where three species were described from the Shara Murun formation. The genus included medium to large brontotheres which had long skulls with nasal horns. Like other solid-horned brontotheres, ''Rhinotitan'' was sexually dimorphic in horn size. In living mammals, this pattern is found in species that live in groups; males have the larger horns, and use them in ritualized combats with other males to decide control of territories that offer breeding access to females. Most horned brontotheres had dish-shaped skulls assumed to be adapted for such combats. However, the skull of ''Rhinotitan'' was concave only near the front; the top and back of the skull was rounded in a way similar to hornless brontotheres. The functional significance of this character is unknown.
It weighed 1.5 tons. Tooth analysis indicates that, like other brontotheres, it was a herbivore adapted to browse on leaves.
References
* ''Classification of Mammals'' by Malcolm C. McKenna and Susan K. Bell
Brontotheres
Eocene odd-toed ungulates
Eocene mammals of Asia
Fossil taxa described in 1943
Brontotheres of Asia
{{paleo-oddtoedungulate-stub