& Nature Photo Galleries
Skeleton of Equus Horse and Outline of Contour of Body[3]
1. Mandible with Teeth
1486 Fd. at horse ranch in Michigan, USA
Note: The following pictures are intended to show the shape details and not the relative sizes.
3. Atlas Vertebra
1548 Fd. ground surface
5. ?th Cervical Vertebra
1471 Fd. with 1474 above
4. Axis Vertebra
1474 Fd. ground surface of farm land in Rhode Island, USA
(Portion of left traverse process is missing.)
1 - mandible; 2 - skull; 3 - atlas vertebra; 4 - axis vertebra; 5 - cervical vertebrae; 6 - 1st thoracic vertebra; 7 - thoracic vertebrae; 8 - lumbar vertebrae; 9 - sacrum; 10 - caudal vertebrae; 11 - pelvis; 12 - femur; 13 - fibula; 14 - tibia; 15 - calcaneum; 16 - astragalus; 17 - metatarsal; 18 - 1st phalanx; 19 - 2nd phalanx; 20 - 3rd phalanx; 21 - coffin; 22 - hoof; 23 - sesamoid; 24 - tarsals; 25 - metacarpal; 26 - carpals; 27 - radius; 28 - ulna; 29 - humerus; 30 - scapula; 31 - ribs. Not all bones have been called out. Some bones have more than one name depending on the nomenclature used by a particular branch of science.
Horses are amazing creatures. They were first domesticated about 3,000 years ago and have been major sources of transportation and used to power equipment such as plows in farming.
Secretariat was the first horse to win the Triple Crown in horse racing (Kentucky Derby, Preakness Stakes, and Belmont Stakes) in twenty-five years and set speed records in all three races.[1] An autopsy at his death indicated his advantage was having a much larger heart than normal.
The heart of a horse is too small for their body size (i.e. will not be able to effectively pump enough blood). Horses have four extra little pumps: one in each hoof. In the hoof, surrounded by hard tissue is a v-shaped soft tissue called a frog. When a horse steps down on a hoof, the soft tissue compresses pushing up against a series of mechanisms inside the hoof and squeezes the blood in the veins up the leg. When the hoof is off the ground, blood flows down the leg.[2]
Equus Horse Skeleton
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[1] Secretariat (Horse), Wikipedia online encyclopedia, as modified May 5, 2014

[2] Incredible Creatures that Defy Evolution, DVD, (Reel Productions, LLC, 2004)

[3] Sisson, Septimus, The Anatomy of Domestic Animals, 2nd Ed. (Philadelphia: W.B. Saunders Co., 1914), 32. The nomenclature used here differs in some cases from that used in this book.   


6. 1st Thoracic Vertebra
1470 Fd. with 1474 above
9. Sacrum
1641 Fd. unknown location
15. Calcaneum
Unidentified Horse (fossil)
      Mirrored views 2.4"x1.0"x0.9"
16. Astragalus
Unidentified Horse (fossil)
1378 Fd. Georgia, USA supposedly
on site with Clovis and Paleo artifacts Mirrored views
2.2"x 2.3" 1.6"x1.7"
1205 Fd. Badlands, South Dakota?, USA
 Mirrored views  1.6"x1.7"     
              1029 Fd. Badlands, South Dakota, USA
1472 Fd. with 1474 above
  1. 9"x2.0"x2.0"