 Reference Base  Tooth replacement and dentition of the black rhinoceros (... |
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Anderson, J.L., 1966. Tooth replacement and dentition of the black rhinoceros (Diceros bicornis Linn). Lammergeyer 6: 41-46, pls. 1-2, figs. 1-2, tables A-B
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| Location: |
Africa - Southern Africa - South Africa |
| Subject: |
Morphology - Size |
| Species: |
Black Rhino |
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Within a collection of fifty-eight black rhinoceros skulls from the Hluhluwe Game Reserve, Zululand, a number of known-age specimens enabled the formulation of ageing criteria based on tooth replacement. Twenty-four of the specimens in the collection showed variation from the normal dental formula, three of these skulls possessing incisors in the lower jaw.
Skulls of known age were from calves whose approximate dates or birth had been noted, and whose mothers' characteristic horn shapes and ear-tears enabled their recognition. The specimen H 30, an animal seven years three months old, was born earless and hence easily recognisable. The stages of tooth replacement in the mandible are shown in Table A.
TABLE A
Tooth eruption in the lower jaw of the Black Rhino.
Coll. No Age Premolars Molars
1 2 3 4 1 2 3
H101 Foetus - (D) (D) - - - -
H100 +3 months (D) (D) (D) (D) - - -
H.40 9 months (D) D D (D) (P) - -
H.11 14 months D D D D (P) (P) -
H. 34 16 months D D D D (P) (P) -
H. 22 18 months (P) D D P P (P) -
H. 46 20 months P D D P P (P) -
H. 47 ?2 years P (P) (P) P P (P) -
H. 18 1 m.m. P P P P P (P) -
H. 39 1 m.m. P P P P P (P) -
H. 30 7 yrs. 3 mo P P P P P P (P)
H.35 Mature P P P P P P P
D - Milk or deciduous tooth; P - Adult or permanent tooth; Brackets indicate tooth in process of eruption.
From this sample it can be seen that at approximately three months of age, all the premolars are in the process of eruption. The second and third premolars are more advanced than the other two. By nine months of age the first molar has begun to erupt, this tooth has fully developed by eighteen months by which time the first permanent premolar and the second molar are erupting.
The remaining milk premolars are replaced at about two years of age. By seven years of age the third molar has almost completely erupted, the remaining teeth being fully developed.
TABLE B
Black Rhino Skull and Mandibular Tooth Measurements
(Measurement in millimetres.)
Note: D - Milk or deeiduous tooth; P - Adult or permanent tooth; BraCkets indicate tooth in the process of erupting; a - tooth absent
A - Greatest length E - Lambloid length
B - Condylobasal length F - Nasal length
C - Zygomatic width G - Nasal width
D - Postorbital constriction H - Mandible length
No Sex Age A B C D E F G H
H101 - foetus - 107 68 53 49 62 151 -
H100 F 3m 243 243 145 77 62 62 75 -
H888 - 3m - - - - - - - 208
H40 F 9m - - - - - - - 263
H11 M 14m 442 423 261 93 142 138 121 341
H34 F 16m - - 260 94 - 141 118 349
H22 M 18m 524 494 298 102 161 161 150 413
H46 F 20m 415 395 247 99 124 115 124 356
H47 M 2y 462 453 261 92 140 153 122 386
H18 M imm - - 276 92 150 171 138 384
H39 M - 451 440 269 96 138 156 130 355
H30 M 7y3m - - 322 114 - 184 170 448
H35 - mat 589 555 331 118 178 181 183 465
H37 M mat 579 542 318 101 184 - - 438
H29 M mat 596 546 313 103 189 190 160 446
H8 M mat 571 529 317 105 184 186 170 445
H16 M mat 616 - 334 120 205 188 186 467
H27 F mat 576 537 338 105 192 190 180 460
H19 F mat 557 535 317 110 185 - - 435
No Sex Age P1.L P2.L P3.L P4.L M1.L M2.L M3.L P2-M3
H101 - foetus (D) (D) - - - - - -
H100 F 3m (D) (D) (D) (D) - - - -
H888 - 3m - (D) (D) (D) - - - -
H40 F 9m (D) 35 43 (D) (P) - - -
H11 M 14m 25 45 52 61 (P) (P) - -
H34 F 16m 20 31 43 44 (P) (P) - -
H22 M 18m (P) 30 39 44 49 (P) - -
H46 F 20m 24 40 46 52 48 (P) - -
H47 M 2y 22 (P) (P) 56 59 (P) - -
H18 M imm 25 41 48 58 56 (P) (P) -
H39 M - 23 38 48 55 53 (P) (P) -
H30 M 7y3m 21 38 50 53 59 67 (P) -
H35 - mat 22 38 48 48 59 60 47 257
H37 M mat 16 28 39 44 51 52 50 250
H29 M mat 18 31 41 45 53 51 46 262
H8 M mat a 29 40 44 53 50 46 265
H16 M mat a 29 39 44 50 49 46 251
H27 F mat a 28 35 41 47 51 47 241
H19 F mat a 32 42 43 50 53 42 266
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