Table 6.
Sexual dimorphism of cranial morphometric measurements (mean ± SD) of Rattus norvegicus and Rattus rattus.
| Sl. No. | Parameters * | Rattus norvegicus | Rattus rattus | ||||
|---|---|---|---|---|---|---|---|
| Female (n = 38) | Male (n = 48) | p | Female (n = 9) | Male (n = 9) | p | ||
| 1 | General cranial length | 46.3 ± 3.7 | 47.1 ± 4.3 | 0.38 | 38.2 ± 2.8 | 36.2 ± 2.2 | 0.11 |
| 2 | Condylobasal length | 44.8 ± 3.6 | 45.5 ± 4.4 | 0.48 | 35.3 ± 3.5 | 35.6 ± 2.3 | 0.83 |
| 3 | Henselion-basion length | 39.3 ± 3.5 | 38.9 ± 3.8 | 0.65 | 29.5 ± 3.8 | 29.2 ± 1.8 | 0.82 |
| 4 | Henselion-palpation length | 22.6 ± 1.9 | 22.2 ± 2.6 | 0.51 | 17.3 ± 1.4 | 16.4 ± 2.0 | 0.25 |
| 5 | Length of upper incisor | 7.5 ± 1.6 | 7.5 ± 1.6 | 0.95 | 5.8 ± 1.1 | 5.4 ± 0.9 | 0.38 |
| 6 | Width of upper incisors, basal | 4.8 ± 0.6 | 4.8 ± 0.6 | 0.77 | 3.6 ± 0.3 | 3.4 ± 0.7 | 0.40 |
| 7 | Width of upper incisors, apex | 3.2 ± 0.5 | 3.3 ± 0.4 | 0.31 | 2.4 ± 0.2 | 2.1 ± 0.4 | 0.08 |
| 8 | Upper incisor to alveolus molar tooth 1 | 14.4 ± 1.8 | 14.4 ± 2.0 | 0.99 | 10.8 ± 1.3 | 9.5 ± 1.4 | 0.06 |
| 9 | Length of diastema | 13.3 ± 1.5 | 13.4 ± 1.5 | 0.77 | 10.2 ± 1.1 | 9.1 ± 1.2 | 0.06 |
| 10 | Nasal bone length | 17.2 ± 1.8 | 17.2 ± 2.0 | 0.89 | 13.0 ± 1.3 | 12.2 ± 1.4 | 0.24 |
| 11 | Breath of nasal bones | 5.1 ± 0.5 | 5.2 ± 0.6 | 0.30 | 4.0 ± 0.1 | 3.8 ± 0.4 | 0.38 |
| 12 | Frontal bone length | 14.6 ± 1.1 | 14.7 ± 1.5 | 0.72 | 12.8 ± 1.5 | 11.7 ± 1.1 | 0.13 |
| 13 | Frontal bone width | 10.8 ± 0.6 | 10.9 ± 0.6 | 0.55 | 10.4 ± 1.2 | 10.2 ± 0.9 | 0.63 |
| 14 | Parietal bone length | 13.0 ± 0.9 | 13.1 ± 1.2 | 0.75 | 11.6 ± 0.6 | 10.9 ± 1.2 | 0.16 |
| 15 | Breath of brain cage | 16.1 ± 2.0 | 16.6 ± 2.3 | 0.33 | 16.1 ± 0.6 | 16.3 ± 0.7 | 0.48 |
| 16 | Interparietal bone length | 6.6 ± 0.9 | 6.4 ± 0.6 | 0.24 | 5.6 ± 0.5 | 5.4 ± 0.7 | 0.51 |
| 17 | Interparietal bone width | 11.4 ± 1.0 | 11.6 ± 1.0 | 0.20 | 10.8 ± 0.8 | 10.6 ± 0.9 | 0.79 |
| 18 | Occipital bone length | 6.0 ± 0.7 | 6.0 ± 0.9 | 0.75 | 4.5 ± 0.5 | 4.5 ± 0.2 | 0.86 |
| 19 | General cranial height | 16.6 ± 1.6 | 16.6 ± 1.5 | 0.97 | 14.1 ± 0.7 | 13.2 ± 0.8 | 0.03 |
| 20 | Rostrum height | 13.8 ± 1.1 | 13.7 ± 1.4 | 0.72 | 11.2 ± 0.7 | 10.4 ± 1.0 | 0.07 |
| 21 | Rostrum breathe | 9.1 ± 0.9 | 9.0 ± 1.1 | 0.74 | 6.7 ± 0.6 | 6.4 ± 0.8 | 0.41 |
| 22 | Smallest interorbital breadth | 6.7 ± 0.4 | 6.9 ± 0.6 | 0.32 | 6.0 ± 0.4 | 5.6 ± 0.3 | 0.04 |
| 23 | Breath of inferior ramus of the zygomatic process of maxillary | 1.8 ± 0.3 | 1.9 ± 0.3 | 0.11 | 1.6 ± 0.2 | 1.4 ± 0.1 | 0.09 |
| 24 | Breath of base zygomatic process of squamosal | 2.9 ± 0.4 | 3.0 ± 0.4 | 0.70 | 2.3 ± 0.4 | 2.1 ± 0.5 | 0.40 |
| 25 | Breadth of zygomatic plate | 5.2 ± 0.5 | 5.0 ± 0.6 | 0.34 | 4.0 ± 0.3 | 3.5 ± 0.8 | 0.08 |
| 26 | Zygomatic breath | 22.4 ± 2.0 | 22.3 ± 2.5 | 0.82 | 18.5 ± 0.8 | 17.9 ± 1.2 | 0.25 |
| 27 | Length of palatal foramen | 7.9 ± 0.7 | 7.8 ± 0.9 | 0.60 | 6.0 ± 1.0 | 6.1 ± 0.8 | 0.69 |
| 28 | Smallest palatal breadth | 4.8 ± 0.6 | 4.6 ± 0.5 | 0.29 | 3.8 ± 0.4 | 3.4 ± 0.4 | 0.06 |
| 29 | Upper cheek-teeth alveoli | 7.3 ± 0.4 | 7.4 ± 0.4 | 0.16 | 6.6 ± 0.4 | 6.7 ± 0.4 | 0.55 |
| 30 | Breadth of upper dental arch | 9.4 ± 0.7 | 9.4 ± 0.7 | 0.57 | 7.8 ± 0.3 | 7.5 ± 0.5 | 0.19 |
| 31 | Breadth of molar tooth 1 | 2.8 ± 1.0 | 2.7 ± 1.0 | 0.84 | 2.0 ± 0.3 | 2.0 ± 0.2 | 0.65 |
| 32 | Tympanic bulla length | 8.1 ± 0.5 | 8.1 ± 0.7 | 0.76 | 7.1 ± 0.6 | 7.1 ± 0.5 | 0.91 |
| 33 | Tympanic bulla width | 6.1 ± 1.1 | 6.0 ± 0.9 | 0.78 | 5.2 ± 0.7 | 5.2 ± 0.6 | 0.99 |
| 34 | Foramen magnum width | 6.8 ± 0.4 | 6.9 ± 0.4 | 0.08 | 6.0 ± 0.3 | 5.8 ± 0.2 | 0.39 |
* The parameters were measured in millimeters; n: Total observation, SD: Standard deviation of mean, and p: Probability at 95% confidence level.