Why is the Other Contributors element now called the Contributor element?

The ninth edition of the MLA Handbook simplifies and clarifies the terminology used to describe some of the elements of a works-cited-list entry. Thus, the element name Other Contributors, used in the previous edition, has been shortened to Contributor. The definition of the element remains the same: a contributor is a person who had a hand in creating the work but is not its primary author. The change in terminology helps clarify that works without a primary author (like an anonymously written work) can have a contributor (like an editor or translator). 

Sections 5.38–5.41 of the MLA Handbook, ninth edition, explain the Contributor element in detail.