Why do some sharks have rows of replaceable teeth?

Many sharks lose teeth regularly because their teeth are not anchored deeply in jaws the way human teeth are. Instead, they are arranged in conveyor-belt-like rows, with new teeth developing behind the front row and rotating forward as needed. This system allows sharks to replace worn or broken teeth quickly, sometimes over and over across a lifetime. Since sharks often feed on tough prey, bones, shells, or struggling animals, replaceable teeth are a major advantage. The arrangement is one reason sharks have been so evolutionarily successful for hundreds of millions of years.