Rat

1. Rat

2. Classification Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most well known are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus. The brown rat also known as the common rat, originated from China is Widespread across all continents except Antarctica. This rat is the dominant rat in most of Europe and North America. The black rat is a common long tailed rodent, thought to originate in tropical Asia. It is largely confined to warmer areas having been supplanted from cooler regions and urban areas by the brown rat. Both brown rats and Black rats are considered omnivores and eat a wide range of foods, including seeds, fruit, stems, leaves, fungi, and a variety of invertebrates and vertebrates. They can breed throughout the year if conditions are suitable, a female producing up to five litters a year. The gestation period is only 21 days and litters can number up to fourteen, although seven is common. They reach sexual maturity in about 5 weeks. The maximum life span is up to three years, although most barely manage one. http://en.wikipedia.org/wiki/Brown_rat http://en.wikipedia.org/wiki/Black_rat

4. 3. 1. 4. 2. 5. 6. 7. 18. 17. 16. 15. 12. 9. 14. 8. 10. 13. 11. 1. Temporal bone 2. Zygomatic bone 3. Zygomatic process frontal bone 4. Frontal bone 5. Nasal bone 6. Premaxilla 7. Maxilla 8. Upper Insisor 9. Lower incisor 10. Three upper molars 11. Three lower molars 12. Mandible 13. Zygomatic process temporal bone 14. Tympanic bulla 15. External auditory meatus 16. Mastoid process 17. Occipital condyle 18. Occipital bone 19. Interparietal bone

8. 1. 2. 3. • Occipital bone • Interparietal • Tympanic bulla • Interaural line • Temporal bone • Bregma • Frontal bone • Zygomatic arch • Premaxilla bone • Nasal bone 4. 5. 6. 7. 8. 9. 10.

9. 1. 2. 3. 4. 5. 6. • Occipital condyle • Bulla • Basioccipital • Eustachian tube • Basisphenoid • Palatine • Jugal 7.