Node "Authored by" select is a cool module that let’s you change the default author selecting autocomplete field to a regular select field. This can be very handy if you have a number of users on the site. Content editors then don’t have to remember the exact names when assigning authorship.

Another cool thing is that you can select for which content type you’d like this transformation to be made. For instance, you might want the article node forms to have simple select lists for choosing the author but want to keep the default autocomplete field for basic pages.

Additionally, you have to specify what kind of users (by the role they are assigned) will be available in this select list - a very handy feature. If you have content types for which you want to restrict authorship to a specific user role, this functionality will help you out.

To get started using this module, install it and configure it at admin/config/node_authored_select/settings. There you will be able to specify for which content types you’d like the select field to be used in the node form and users of which role should be present in this list. Save the changes and then create (or edit) a new node of that type and you’ll see the change in action.

One thing you should keep in mind though is that if you specify that authenticated users should be present in the select list, administrators won't appear. I suppose this is both good and bad. It's good because it allows you to restrict the list to the exact roles you'd like and bad because if you want all the users of a certain role or higer, you can't. Perhaps it would be nice to be able to select multiple role types to allow for this. I actually opened an issue to see what the maintainer thinks.

Hope this helps.