Horse

The Horse is a single-hooved (ungulate) mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today. Horses in the subspecies caballus are domesticated, although some domesticated populations live in the wild as feral horses. These feral populations are not true wild horses, as this term is used to describe horses that have never been domesticated, such as the endangered Przewalski’s Horse, a separate subspecies, and the only remaining true wild horse.

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Subclass: Theria

Infraclass: Eutheria

Order: Perissodactyla

Family: Equidae

Genus: Equus

Species: E. ferus

Subspecies: E. f. caballus

Classification

The horses' anatomy enables them to make use of speed to escape predators and they have a well-developed sense of balance and a strong fight or flight instinct. Related to this need to flee from predators in the wild is an unusual trait: horses are able to sleep both standing up and lying down. gestation lasts for approximately 335–340 days and usually results in one foal, twins are rare in horses. Horses are a precocial species, and foals are capable of standing and running within a short time following birth. Horses are herbivores with a digestive system adapted to a forage diet of grasses and other plant material, consumed steadily throughout the day. Therefore they have a relatively small stomach but very long intestines to facilitate a steady flow of nutrients.

http://en.wikipedia.org/wiki/Horse

Skull and mandible of a horse, lateral view

1. Facial crest2. Fossa for lacrimal soc3.Zygomatic arch4. Zygomatic process of frontal bone5.Articular tubercle6. Mandibular fossa7. External sagittal crest8. Nuchal crest

1.

10.

9.

8.7. 6. 5. 4. 3. 2.

11.

21.

22.

14.

15.

16.

17.

13.12.

19.18.20.

9. Temporal fossa 10. Coronoid process11. External acoustic meatus12. Mastoid process13. Condyloid fossa14. Occipital condyle15. Jugular process16. Condylar process

17. Mandibular notch 18. Ramus of mandible19. Angle of mandible20. Retroarticular process21. Mental foramen22. Nasal process of incisive bone23. Infraorbital foramen24. Nasoincisive notch

23.

24.

2.

3.

1.

4.

Skull and mandible of a horse, lateral view

1. Body of incisive bone2. Incisor teeth3. Interalveolar border4. Premolar teeth5. Molar teeth

5.

1.

2.

3.

5.

6.

7.

8.

9.

4.

13.

12.

11.

10.

15.

14.

16.

1. External occipital protuberance

2. Nuchal crest3. Coronoid process4. Mandibular fossa5. Condylar process6. Jugular process7. Caudal alar

foramen8. Hamulus of

pterygoid9. Body of mandible10. Angle of mandible11. Mandible foramen12. Ramus of

mandible13. Choanae14. Foramen magnum15. Occipital condyle16. Zygomatic arch

Skull and mandible, caudal view

1.Interincisive canal2. Body of incisive bone3. Nasal process of incisive bone4. Infraorbital foramen5. Facial crest6. Orbit7. Zygomatic process of frontal bone8. Zygomatic arch

9.Temporal line10. Nuchal crest11. External saggital crest12. Temporal fossa13. Supraorbital foramen14. Rostral lacrimal process15. Nasoincisive notch

1.

2.

3. 4. 5. 6. 7. 8. 9.

11.

10.

12.

13.14.15.

11.12.

13.

2. 3.4.

5.6. 7. 8. 9.

11.

10.

12.

1.Incisor teeth (11. 12. 13)

2. Palatine process of maxilla3. Rostral end of facial crest4. Choanae5. Vomer6. Wings of vomer

7. Hamulus of pterygoid bone8. Caudal alar foramen9. Tympanic bulla10. Foramen magnum11. Occipital condyle12. External acoustic meatus

Skull of horse, ventral view