''Rusingaceros'' or ''Dicerorhinus leakeyi'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of rhinocerotine

rhinoceros A rhinoceros (; ; ), commonly abbreviated to rhino, is a member of any of the five extant species (or numerous extinct species) of odd-toed ungulates in the family Rhinocerotidae. (It can also refer to a member of any of the extinct species ...

known from the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Rusinga Island Rusinga Island, with an elongated shape approximately 10 miles (16 km) from end to end and 3 miles (5 km) at its widest point, lies in the eastern part of Lake Victoria at the mouth of the Winam Gulf. Part of Kenya, it is linked to Mbita ...

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi ...

Discovery

''Rusingaceros'' is known from the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

KNM-RU 2821, an almost perfectly preserved

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

and associated

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

and from the

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). O ...

KNM-RU 2822, a

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. T ...

and associated mandible. Both specimen were collected in the early

site (

Burdigalian The Burdigalian is, in the geologic timescale, an age or stage in the early Miocene. It spans the time between 20.43 ± 0.05 Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian, the Burdigalian was the first and longest w ...

stage) of

Rusinga Rusinga Island, with an elongated shape approximately 10 miles (16 km) from end to end and 3 miles (5 km) at its widest point, lies in the eastern part of Lake Victoria at the mouth of the Winam Gulf. Part of Kenya, it is linked to Mbita ...

located in Lake Victoria in Kenya, from the Kulu Formation, dating to about 17.5

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago) ...

. Additional specimens described by Hooijer in 1966 from the Songhor and Napak localities, as well as more recently reported occurrences, are highly fragmentary and based mostly on isolated teeth. ''Rusingaceros'' represents the earliest rhino "of modern type, i.e., with a strong nasal and smaller frontal horn". This suggests that ''Rusingaceros'' belongs to subtribe Rhinocerotina, within the tribe Rhinocerotini.

Etymology

''Rusingaceros'' was first named by Denis Geraads in 2010 and the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

is ''Rusingaceros leakeyi''. It was originally described by Hooijer in 1966 as a new species of ''

Dicerorhinus ''Dicerorhinus'' (Greek: "two" (dio), "horn" (keratos), "nose" (rhinos)) is a genus of the family Rhinocerotidae, consisting of a single extant species, the two-horned Sumatran rhinoceros (''D. sumatrensis''), and several extinct species. The g ...

''. The generic name is derived from the name of

, and from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''ceros'', "horn", thus, the name means "Rusinga Island's horn". The specific name honors Leakey.

References

{{Taxonbar, from=Q7380914 Fossil taxa described in 2010 Miocene mammals of Africa Miocene rhinoceroses