When vertebrae cross dress: How sloths got their long neck

http://www.biologynews.net/archives/2010/10/18/when_vertebrae_cross_dress_how_sloths_got_their_long_neck.html


Summary

From out of 5000 species of mammals, three toed sloths are one of the few that have more than 7 vertebrae in their neck. They can have up to ten vertebrae. Scientists at the university of cambridge are investigating the development in the mamals skeleton. The bottom "neck" vertebrae of sloths are developmentally the same as ribcage vertebrae of other mammals, but lack ribs. Bone formation started earlier in sloths than in other mammals.


Opionion

I think this is interesting because it pertains to me. Also, I never would have guessed sloths would be so different. I always thought they were boring and not interesting, but I was proved wrong. It's extremely interesting and shocking how three toed sloths have more vertebrae in the neck than giraffes. It's also very different how sloths lack ribs.