MadSci Network: Zoology |
It took some doing but with the help of my colleague Steve Myers here at Valencia Community College we contacted experts on mammals until we got a definitive answer. According to Don E. Wilson in the Division of Mammals at the Smithsonian Institution in Washington, DC, to say that the the three-toed sloth can turn its head through an arch of 270 degrees means 135 in each direction from facing forward, a little less than looking straight backwards, as you surmised.
Try the links in the MadSci Library for more information on Zoology.