. Bulletin of the British Museum (Natural History), Geology. RHINOCEROSES 419 indentation between metalophid and hypolophid. As regards reduction of the anterior pre- molars, even P2 has diminished in size (Heissig 1976: 33, fig. 2). Paradiceros mukirii was described as an early relative of the living African black rhinoceros, Diceros bicornis, apparently about twice as old as the well-known Turolian Diceros pachygnathus. Paradiceros differs most notably from the Arabian species by the absence of lower incisors. Other differences are its shorter premolar row without a Pl7 stronger antero- ling
. Bulletin of the British Museum (Natural History), Geology. RHINOCEROSES 419 indentation between metalophid and hypolophid. As regards reduction of the anterior pre- molars, even P2 has diminished in size (Heissig 1976: 33, fig. 2). Paradiceros mukirii was described as an early relative of the living African black rhinoceros, Diceros bicornis, apparently about twice as old as the well-known Turolian Diceros pachygnathus. Paradiceros differs most notably from the Arabian species by the absence of lower incisors. Other differences are its shorter premolar row without a Pl7 stronger antero- lingual cingula on the lower premolars, and probably the larger crochets of the upper molars. It is not clear why Rhinoceros browni need be generically separated from Dicerorhinus as used here (cf. Groves 1983: 310). Alleged differences are that it has no sign of a horn base on the frontals, the top of the nasals are less bent downwards and the anterior border of the orbit lies above the middle of M1. The first two characters resemble later Rhinoceros but could as easily fit a female Dicerorhinus. As to the third, the front of the orbit lies above P4 in adult modern R. unicornis, above M1, perhaps even its back half, in D. sumatrensis, and above the M7M2 boundary in Miocene Dicerorhinus. Here again the state of R. browni could fit Dicero- rhinus as easily as Rhinoceros. The union of the posttympanic and postglenoid processes beneath the external auditory meatus, mentioned by Colbert (1934), is like Rhinoceros and Miocene Dicerorhinus but unlike D. sumatrensis. Modern R. unicornis and sondaicus have a longer P3 and P2 than D. sumatrensis (Guerin 1980: table 5) but there is no foreshadowing of this in R. browni. Rhinoceros browni differs from the Arabian species in having a smaller crochet and curved ectometaloph on M3, a shorter premolar row, a more prominent metacone rib on the upper premolars and probably a stronger mesostyle rib on the upper molars. Crochet size on M1 and M2 of R
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