Urtinotherium
- East Asia: northern China, Mongolia
- Central Asia: Kazakhstan
- South Eastern Europe: Romania
- Urtinotherium incisive Chow & Chiu, 1963
Urtinotherium is an extinct genus of the extinct subfamily also the Indricotheriinae, which was closely related to the current rhinos and partially trained giant forms. The genus lived from the late Eocene to middle Oligocene about 37 to 30 million years ago and was spread over East and Central Asia.
Features
Urtinotherium was a great representative of the Indricotheriinae and reached nearly the dimensions of Paraceratherium. It is known from finds from East and Central Asia, complete skeletons are not available, however. The holotype ( IVPP V.2769 copy number ) includes a complete lower jaw. This was 72 cm long and thus had a slightly shorter length than that of Paraceratherium that measured in large specimens a total of 83 cm. He had a wedge-like shape and was very elongated lower jaw body had a relatively small height. The symphysis was made solid and handed up to the beginning of the second premolars. He had the complete dentition earlier mammals. This was the front teeth from three incisors and one canine. Here, the inner incisor pair was directed forward and significantly enlarged and with a crest length of 4.9 cm, so that it had a dagger- like shape. The other incisors and the canine, however, were significantly smaller. Between each tooth was similar to its phylogenetically older relatives Juxia a small gap. The posterior dentition, which was separated by a small diastema also from the front, consisted of four premolars and three molars. These were similar in structure to those of Paraceratherium with small and large molars Vomahl. The latter were clearly niederkronig and had little folded enamel.
Fossil finds
Remains of Urtinotherium come mainly from East and Central Asia, there are but usually only jaw fragments and isolated teeth before. The holotype lower jaw was found in the early 1960s in the Urtyn - Obo Formation of the early to middle Oligocene in Inner Mongolia ( China). Other discoveries came in Yunnan ( China also ) and in späteozänen deposits of Khoer - Dzam in Mongolia to days. Furthermore, recent findings from Aksyir Svita originate in Saissansee Basin in eastern Kazakhstan and also have a späteozänes age on. Its westernmost area of distribution reached Urtinotherium probably in South-Eastern Europe, where it was detected in the früholigozänen Mera lineup at Fildu de Sus in Salaj county in Romania.
System
Urtinotherium belongs to the subfamily Indricotheriinae and to the family of Hyracodontidae. These in turn are part of the superfamily Rhinocerotoidea and thus represent close relatives of today's rhinos dar. Of these differ the Hyracodontidae by the formation of each of a pair of large dagger -shaped incisors in the upper and lower jaw, while the Rhinocerotidae have only one such pair in the lower jaw.
The genus represents an early form of Indricotherien and evolved in the late Eocene. She probably goes back to Juxia from the Middle Eocene of North China, with whom she shares the full Säugetierbezahnung of the mandible. Differences are much larger physique and greater specialization of the incisors at Urtinotherium. From Urtinotherium later Paraceratherium, the largest known land mammal developed. This includes over Urtinotherium on a significantly reduced dentition with only one pair of incisors in the lower jaw. The recent findings of this large rhino -like come from the Middle Oligocene.
The first description was in 1963 by Urtinotherium of Chow Chiu Chan - siang and Minna basis of the lower jaw from the Urtyn Obo formation. The only recognized type is Urtinotherium incisive dar. The generic name is in this case from the term for the same reference and the Greek word θηρίον ( Therion ) for " animal " together. The types of arms refers to the elongated incisors (Latin incisor ).