Miscellaneous Animals Skeleton
American bison characteristics: Has very long spinous processes on thoracic vertebrae (especially between the shoulders). Four digits with hoofs per limb. Two central toes are large and weight-bearing; vestigial inner and outer toes, with hoofs, are very small and located higher on side of foot and to the rear (they do not articulate with the skeleton and do not touch the ground). Walks on toes. Front half of body develops permanent long hair, especially on the top of the skull, the chin, and the forearms). Rear half looses thick fur cover in the summer, so difference between hair length of front and rear portions of body is very pronounced in warm months, with a clear line of demarcation. Both sexes have horns. African elephant characteristics: Middle of back profile concave/low (convex/high in Indian). Nose extends into long, flexible, muscular trunk with nostrils and one prehensile finger-like projection at tip (two in Indian). Large skull; short nasal bones located high on skull (for attachment of trunk). Brain surrounded by thick, airy bone. Single rounded prominences on top of head (double in Indian). Upper incisors elongated into continuously growing tusks, in both male and female. Very large ears (larger than Indian). Short neck—cervical vertebrae compressed front to back. Rib cage extends to pelvis. Thick, pillar-like columnar limbs (bones in almost vertical straight line) and shoulder and hip sockets face downward, all to support massive body weight. Short feet. All feet have five digits—some inner and outer toes may be reduced and without hoofs. Both front and rear feet have an extra small, elongated bone (prepollex in front and prehallux in rear) just to the inside of the first digit. Front foot has four or five hoofs (five in Indian). Hind foot usually has three, four, or five hoofs (four or five in Indian). Thick elastic pad on sole of foot. Foot in life somewhat cylindrical or conical. When the animal is lying on belly, knee touches ground (femur directed downward); lower leg continues straight back. Long tail has wispy tuft of coarse hair.