Pachynolophus, Palaeotherium, Paraceratherium, Indricotherium and Juxia

Pachynolophus eulaliensis (Pomel 1847, Danilo et al. 2013; Eocene) is widely considered a horse relative, but here nests basal to the giant horses, Juxia + Paraceratherium. It is presented here about life size on a 72 dpi screen monitor.

Palaeotherium magnum (Cuvier 1804; Early to Middle Eocene) was considered close to horses, but here nests basal to Juxia + Paraceratherium. The central digit was no larger than the lateral digits. Note the long neck and long naris. The anterior dentary teeth do not erupt from a descending jaw tip. The central incisors are larger than the lateral ones.

Paraceratherium transouralicum (P. bugtiense holotype, Pilgrim 1908; Baluchitherium, Osborn 1923; late Oligocene, 34-23mya; 4.8m shoulder height, 7.4m long) was long considered a giant hornless rhinoceros, but here nests with the horse, Equus. They share a long neck, straight ventral dentary and the retention of premaxillary teeth, among other traits. Paraceratherium retains three toes, as in ancestral horse/rhinos like Heptodon and Hyracotherium.

Juxia sharamurenense (Chow and Chiu 1964; IVPP V2891; Upper Eocene, below) half the size of Paraceratherium with a skull the size of a horse skull, Juxia was more lightly built and derived from a sister to Miohippus. Juxia had three premaxilary teeth.

Chow M and Chiu C-S 1964. An Eocene giant rhinoceros. Vertebrata Palasiatica, 1964 (8): 264–268.

Cuvier G 1804. Ann. Mus. Hist. Nat. (Paris), 3 (16).

Danilo L et al. 2013. A new Eocene locality in southern France sheds light on the basal radiation of Palaeotheriidae (Mammalia, Perissodactyla, Equoidea), Journal of Vertebrate Paleontology, 33:1, 195-215.

Forster-Cooper C 1911. LXXVIII.—Paraceratherium bugtiense, a new genus of Rhinocerotidae from the Bugti Hills of Baluchistan.—Preliminary notice. Annals and Magazine of Natural History Series 8. 8 (48): 711–716. doi

Forster-Cooper C 1924. On the skull and dentition of Paraceratherium bugtiense: A genus of aberrant rhinoceroses from the Lower Miocene Deposits of Dera Bugti. Philosophical Transactions of the Royal Society B: Biological Sciences. 212 (391–401): 369–394.

Granger W and Gregory WK 1935. A revised restoration of the skeleton of Baluchitherium, gigantic fossil rhinoceros of Central Asia. American Museum Novitates. 787: 1–3.

Lucas SG and Sobus JC 1989. The Systematics of Indricotheres". In Prothero DR and Schoch RM eds. The Evolution of Perissodactyls. New York, New York & Oxford, England: Oxford University Press: 358–378. ISBN 978-0-19-506039-3.

Osborn HF 1923. Baluchitherium grangeri, a giant hornless rhinoceros from Mongolia. American Museum Novitates. 78: 1–15. PDF

Pilgrim GE 1910. Notices of new mammalian genera and species from the Tertiaries of India. Records of the Geological Survey of India. 40 (1): 63–71.

Pomel A 1847. Notes sur les mammiferes et reptiles fossiles des terrains eocenes
de Paris, inferieurs au depot gypseux.Archives des Sciences Physiques et Naturelles de Gen`eve 4:326–330.

Wood HE 1963. A primitive rhinoceros from the Late Eocene of Mongolia. American Museum Novitates 2146:1-11.

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