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.

Skull and mandible of a horse, lateral view 1. Facial crest 2. Fossa for lacrimal soc 3.Zygomatic arch 4. Zygomatic process of frontal bone 5.Articular tubercle 6. Mandibular fossa 7. External sagittal crest 8. Nuchal crest Temporal fossa 10. Coronoid process 11. External acoustic meatus 12. Mastoid process 13. Condyloid fossa 14. Occipital condyle 15. Jugular process 16. Condylar process 17. Mandibular notch 18. Ramus of mandible 19. Angle of mandible 20. Retroarticular process 21. Mental foramen 22. Nasal process of incisive bone 23. Infraorbital foramen 24. Nasoincisive notch

Skull and mandible of a horse, lateral view 1. Body of incisive bone 2. Incisor teeth 3. Interalveolar border 4. Premolar teeth 5. Molar teeth 5.

External occipital protuberance 2. Nuchal crest 3. Coronoid process 4. Mandibular fossa 5. Condylar process 6. Jugular process 7. Caudal alar foramen 8. Hamulus of pterygoid 9. Body of mandible 10. Angle of mandible 11. Mandible foramen 12. Ramus of mandible 13. Choanae 14. Foramen magnum 15. Occipital condyle 16. Zygomatic arch Skull and mandible, caudal view

1.Interincisive canal 2. Body of incisive bone 3. Nasal process of incisive bone 4. Infraorbital foramen 5. Facial crest 6. Orbit 7. Zygomatic process of frontal bone 8. Zygomatic arch 9.Temporal line 10. Nuchal crest 11. External saggital crest 12. Temporal fossa 13. Supraorbital foramen 14. Rostral lacrimal process 15. Nasoincisive notch

Incisor teeth ( ) 2. Palatine process of maxilla 3. Rostral end of facial crest 4. Choanae 5. Vomer 6. Wings of vomer 7. Hamulus of pterygoid bone 8. Caudal alar foramen 9. Tympanic bulla 10. Foramen magnum 11. Occipital condyle 12. External acoustic meatus Skull of horse, ventral view