The time it takes for a shark use and lose each tooth varies, depending on the species and age. Younger sharks replace their teeth more often. There is also some evidence that sharksâ teeth last significantly longer during colder water temperature in some sharks, a time when they traditionally eat less.
Last Titanic survivor, a baby put in a lifeboat, dies at 97. Millvina Dean taken ill with pneumonia in England, after Hollywood stars DiCaprio and Winslet came to her aid. Millvina Dean, the last living survivor of the Titanic disaster, with a painting of the vessel. Photograph: John Stillwell/AP.
Unseen Titanic. At 2:20 a.m. on April 15, 1912, the âunsinkableâ R.M.S. Titanic disappeared beneath the waves, taking with her 1,500 souls. One hundred years later, new technologies have revealed the most complete and most intimate images of the famous wreck. This story appears in the April 2012 issue of National Geographic magazine.