How many vertebrae does a Giraffe have? The difficulty you have had in finding the number of vertebrae in the giraffe is understandable. Giraffe anatomy is not something people usually study, so I don’t think there are any books on the subject. It also means that I can’t give you an absolute answer (I don’t study giraffe anatomy either). However, I can give you the basic rules for mammalian anatomy, and there is no reason to believe that giraffes will violate these rules. The first, and firmest, rule is that mammals have 7 cervical (neck) vertebrae. This is true of giraffes (they are frequently cited as an example about this rule) and is true of most other mammals. Only the tree sloth and the manatee violate this rule. Going down the vertebral column are the thoracic and lumbar vertebrae. The thoracic vertebrae are the ones that hold the ribs, while the lumbar vertebrae do not. The number of vertebrae in each of these categories varies quite a bit among mammals. For this reason many comparative anatomists combine these two categories as the dorsal vertebrae. The total number of dorsal vertebrae also varies, but is usually fairly constant among mammalian families. Ungulates (the hoofed mammals) almost always have 19 dorsal vertebrae (some have 18 and some have 20, but most have 19). Since the giraffe is an ungulate I am going to guess that they too have 19 dorsal vertebrae. The next section down the vertebral column is the sacrum. In mammals the sacrum is formed by the fusion of 3 to 5 vertebrae. Humans have 5 sacral vertebrae. I am not sure about giraffes, so I am going to guess that they have 4. The real problem comes with the tail. Each tail bone is a vertebra (the caudal vertebrae) and the number here can be extremely variable. Although species generally focus on a similar number, the number of caudal vertebrae can vary between individuals. I can find no reference for the number of caudal vertebrae that you could expect to find in a giraffe. I am going to guess 20, just because that seems to be a fairly common number among mammals. So, my best guess is that a typical giraffe will have 50 vertebrae. Reference: Romer & Parsons (1986) The Vertebrate Body. 6th Edition.
Try the links in the MadSci Library for more information on Zoology.