 Reference Base  Niah Cave animal bone, VIII: Rhinoceros in late quaternar... |
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Medway, Lord, 1965. Niah Cave animal bone, VIII: Rhinoceros in late quaternary Borneo. Sarawak Museum Journal 12 (25/26): 77-82, pl. 21
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| Location: |
Asia - South East Asia - Malaysia - Sarawak |
| Subject: |
Taxonomy - Evolution |
| Species: |
Sumatran Rhino |
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The presence of rhinoceros among the animal remains from the Sarawak Museum excavation in the West Mouth of Niah cave (see Harrisson. 1964, and also previous issues of the S.M.I. for background information), has already been demonstrated by the identification of fragmentary molar teeth (Medway, 1958), several phalanges and a radius (Mcdway, 1959). Since the publication of these reports, the collection of maminalian bone from the excavation has been examined in further detail, and additional material has been identified.
Material from Niah
All stratified material from the West Mouth site is listed in Table 1. It can be, seen that rhinoceros remains occur at all levels from subsurface to a depth of 72 inches. In the central area of the excavation the 72 inch level is associated with a palaeolithic culture, and charcoal samples have yielded a C14 date of 30,673 + 700 B.C. (Harrisson, 1959).
In historic times, the only rhinoceros recorded from Borneo is the Surnatran or Asiatic Two-horned Rhinoceros, Didermocerus sumatrensis (Fischer) (Chasen, 1940; Ellerman & Morrison-Scott, 1955). The Bornean population is separable on skull characters from animals of Sumatra. and has recently been recognised as a distinct subspecies (Groves, 1965). In addition, the Javan or Lesser One-horned Rhinoceros, Rhinoceros sondaicus Desmarest, also occurred within the region in historic times, on Java, Sumatra and the Malay Peninsula. Material from the Niah excavation has already shown that one large ungulate, the, tapir, nowadays restricted to Sumatra and parts of continental Asia, extended to Borneo during the late Upper Pleistocene and early Holocene (Medway, 1960). It is therefore not impossible that the range of the Javan Rhinoceros formerly included Borneo, and the specific identification of the remains from Niah is accordingly of interest.
In general, the existing Javan Rhinoceros is a larger animal than the Surnatran, and many elements of the postcranial skeleton of recent specimens can be separated by size. But evidence from excavations in Sumatra has indicated that it is not possible to identify prehistoric material solely by comparison with the measurements of recent specimens. Hooijer (1946) has noted that subfossil teeth of D. sumatrensis from Sumatran cave deposits tend to be larger than comparative material of recent specimens from that island. He also recorded a humerus of sumatrensis that was 17 percent longer than the largest humerus of recent specimens in the collections of the Leiden museum, exceeding also the length of the humeri of four specimens of recent sondaicus. Evidently in this rhinoceros, as among other mammals of the region (Hooijer, 1949), evolution from the end of the Pleistocene has been towards a progressive reduction in body size.
TABLE 1
Stratified remains of rhinoceros from the West Mouth excavation, Niah
Item Trench Depth
(inches)
1. Fragmentary lateral proximal phalanx E/C3 0-24
2.* Proximal part of right metacarpal IV E/W9 6-12
(fossilised, presumably not in situ)
3. Fragmentary cheek tooth, unerupted E/G6 12-24
4. Fragmentary lower molar, worn E/B3 24-36
5.* Juvenile left metatarsal 11, without E/C2 24-48
distal epiphysis
6. Fragmentary cheek tooth, little worn D/E2 24-48
7. Fragmentary lower molar, unerupted E/WI 30-33
8. Fragmentary lower molar, little worn EIGI 36-42
9. Fragmentary lower molar, unerupted E/B5 42-48
10. Fragmentary cheek tooth EIGI 48-60
11. Distal articulatory face of a lateral E/C2(C) 48-60
proximal phalanx
12. Fragmentary central proximal phalanx E/C2(C) 48-60
13*. Fragmentary left ectocuneiform Y/3 54-60
14. Central proximal phalanx, probably of E/C3(A) 60-66
left hind foot
15. Fragmentary cheek tooth E/BI 60-72
It is therefore unfortunate that the Niah material includes no remains that can be assigned confidently to one or other of the two rhinoceros species on anatomical characters. Only one more or less complete long bone has been excavated at Niah. This was a radius, found in association with a burial (and hence unstratified) in which it served as a ?pillow' (see illustration and discussion in Harrisson, 1957, p.164). This bone has been partly crushed in situ, and no specifically diagnostic characters can be recognised. The total length (350 mm, see Medway, 1959), is compatible with recent D. sumatrensis.
The stratified material from the West Mouth, listed at Table 1 (excluding items 1, 5 and 13, identified by Dr. D. A. Hooijer), together with a central subterminal phalanx from the Lobang Angus mouth (trench US/22, at 18 - 24 inches), has been compared with skeletons of recent D. sumatrensis and Rh. sondaicus in the collection of the British Museum (Natural History). Post-cranial remains comprise a series of small bones of both fore and hind feet, many of them fragmentary. These cannot be ascribed to either species on anatomical characters, and such measurements as can be taken are either compatible with measurements of their homologues in the available skeletons of recent D. sumatrensis, or at the most slightly larger. As noted above, it is to be expected that the bones of prehistoric rhinoceroses from this region should be slightly larger than comparable recent material, and this alone cannot be accepted as indication of the presence of Rh. sondaicus.
In a study of dental material, Hooijer (1946) has noted several specifically distinct characters in the anatomy of the upper (= maxillary) first and second molars, premolars and posterior deciduous molars, which can be used to separate the two rhinoceroses. Unfortunately again, no complete teeth occur in the Niah remains. The only fragments on which representative measurements could possibly be taken are lower (= mandibular) molars, for which Hooijer found no specifically diagnostic characters.
In summary, there is thus from Niah evidence that a small rhinoceros of approximately the same size as, or fractionally larger than the existing Sumatran or Asiatic Two-horned Rhinoceros, D. sumatrensis, has been present in Borneo since at least the close of the Upper Pleistocene era. Subfossil molar teeth from southwestern Sarawak - which though undated can be accepted as more or less contemporaneous with the Niah material - confirm the presence of D. sumatrensis. None of the available material can be attributed to the larger Javan Rhinoceros, Rhinoceros sondaicus, and there is no present evidence that this species extended its range across the Sunda region to reach the Bornean landmass.
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